A quick navigation guide to the files in the repository.
// Write a program (WAP) to print the sum and product of digits of an integer.
// Author - Amit Dutta, Date - 13th SEP, 2025
#include<stdio.h>
int main() {
int inp, result_sum = 0, result_product = 1, temp;
printf("Please enter the number : ");
scanf("%d",&inp);
printf("\n");
if (inp < 0) {
printf("\nPlease enter a valid non negetive integer.");
return 1;
}
temp = inp;
while (temp != 0 ) {
result_sum = result_sum + (temp % 10);
result_product = result_product * (temp % 10);
temp = temp / 10;
}
printf("\nSum of the digits of the input number '%d' is : %d"
"\nProduct of the digits of the input number '%d' is : %d",
inp, result_sum, inp, result_product);
return 0;
}
//WAP to reverse a non-negative integer.
// Author - Amit Dutta, Date - 13th SEP, 2025
#include<stdio.h>
int main() {
int inp, result = 0, temp;
printf("PLease enter the number you want to reverse : ");
scanf("%d",&inp);
printf("\n");
if (inp < 0) {
printf("\nPlease enter a non negetive integer.");
return 1;
}
temp = inp;
while ( temp != 0) {
result = (result * 10) + (temp % 10);
temp = temp / 10;
}
printf("\nReverse of the input '%d' is : %d", inp, result);
return 0;
}
// WAP to compute the sum of the first n terms of the following series S =1+1/2+1/3+1/4+......
// Author - Amit Dutta, Date - 13th SEP, 2025
#include<stdio.h>
int main() {
int n, i;
float result = 0;
printf("Please enter the value for 'n' : ");
scanf("%d", &n);
printf("\n");
if (n <= 0) {
printf("\nPlease enter a positve number greater than ZERO.");
return 1;
}
for (i = 1; i <= n; i++) {
result = result + (1.0 / i);
}
printf("\nSum of the first %d terms of the following series S =1+1/2+1/3+1/4+...... is : %f",n,result);
return 0;
}
//WAP to compute the sum of the first n terms of the following series,S =1-2+3-4+5......
// Author - Amit Dutta, Date - 13th SEP, 2025
#include<stdio.h>
int main() {
int n, result = 0, temp, i;
printf("Please enter the value for 'n' for this series 's = 1-2+3-4+5-....': ");
scanf("%d",&n);
printf("\n");
if (n <= 0) {
printf("\nPlease enter a positive integer.");
return 1;
}
for (i = 1; i<= n; i++) {
if (i % 2 == 0) {
result = result - i;
}
else {
result = result + i;
}
}
printf("\nAns : %d", result);
}
/*Write a function to find whether a given no. is prime or not.
Use the same to generate the prime numbers less than 100.*/
// Author - Amit Dutta, Date - 13th SEP, 2025
#include<stdio.h>
int isPrime(int inp) {
int i, is_prime = 1;
if (inp < 2) is_prime = 0;
for (i = 2; i <= inp / 2; i++) if (inp % i == 0) {
is_prime = 0;
break;
}
return is_prime;
}
int main() {
int inp, i;
printf("Enter the number you want to check : ");
scanf("%d",&inp);
printf("\n");
if (isPrime(inp)) printf("\nGiven input '%d' is a Prime Number.",inp);
else printf("\nGiven input '%d' is not a Prime Number.",inp);
printf ("\nSeries of prime number upto 100 : ");
for (i = 2; i < 100; i++) if (isPrime(i)) printf(" %d",i);
return 0;
}
/*Write a function that checks whether a given string is Palindrome or not.
Use this function to find whether the string entered by the user is Palindrome or not.*/
// Author - Amit Dutta, Date - 13th SEP, 2025
#include<stdio.h>
#include<string.h>
int isPalindrome(char inp[]) {
int len = strlen(inp);
int i = 0; //starting point
int j = len - 1; //end point
while (i < j) {
if (inp[i] != inp[j]) {
return 0;
}
i++;
j--;
}
return 1;
}
int main() {
char inp[20];
printf("Enter the number : ");
scanf("%s",inp);
if (isPalindrome(inp)) printf("\n\nInput '%s' is a Palindrome number.", inp);
else printf("\n\nInput '%s' is not a Palindrome number.", inp);
return 0;
}
// WAP to compute the factors of a given number
// Author - Amit Dutta, Date - 13th SEP, 2025
#include<stdio.h>
#include<stdlib.h>
int main() {
int inp, num, i;
printf("Please enter the number to get the factors from it : ");
scanf("%d", &inp);
num = abs(inp);
if (num == 0) {
printf("\n\n0 has infinitely many factors (all integers).");
return 1;
}
printf("\n\nThe factors of ' %d ' is :- ", inp);
printf("\nPositive : ");
for (i = 1; i <= num ; i++) if (num % i == 0) printf(" %d", i);
printf("\nNegative : ");
for (i = 1; i <= num ; i++) if (num % i == 0) printf(" %d", -i);
return 0;
}
/* A smart home security controller monitors the state of several sensors to decide what action to take.
* Each second, the system reads data from sensors that can either be active or inactive. Based on the current
* state of all sensors, the controller must perform exactly one action, such as activating a warning, checking
* a specific zone, or declaring an intrusion. Write a C program that reads the sensor states as input and
* prints the corresponding system action.
-- Conditions:
* 1. You must determine exactly one action for every possible combination of sensor states.
* 2. You are not allowed to use any conditional statements (if, else if, else, or the ternary operator?).
* 3. You are not allowed to use logical operators.
* 4. You must use a single switch statement to control the program's behaviour.
* 5. Loops may only be used for reading input, not for making decisions.
* 6. The program should handle all possible combinations of the sensors' active/inactive states and print the appropriate response each time.
-- Example (for understanding):
* If all sensors are inactive, the system should remain idle.
* If some sensors are active, the system should issue warnings or alerts based on the situation.
* If all sensors are active, the system should declare a confirmed intrusion.
*/
/*
* This program monitors the state of four sensors (Door, Window, Motion, Glass Break)
* and determines the appropriate action without using any conditional (if, else)
* or logical (&&, ||) operators.
*
* It works by combining the state of all sensors into a single integer value
* using bitmasking. Each bit in the integer represents the state of one sensor
* (1 for active, 0 for inactive). This combined state is then used in a single
* switch statement to select the correct action for every possible combination.
*
* Then, enter the state of the four sensors separated by spaces,
* for example: 1 0 1 0
*/
/* Author - Amit Dutta, Date - 12th October, 2025 */
#include <stdio.h>
int main()
{
// variables to hold the state of a sensor (0 or 1)
int doorSensorState, windowSensorState, motionSensorState, glassbreakSensorState;
// variable to check the combined state of all four sensor
int combinedState = 0;
// a invalid flag to check the input are valid or not
unsigned int invalidFlag;
// printing the way to usage the program
printf("------ Home Security Controller ------\n");
printf("Enter sensor states (1 for active, 0 for inactive).\n");
printf("Format: [Door] [Window] [Motion] [Glass Break]\n");
printf("Example: 0 1 1 0\n");
printf("Enter states (or press Ctrl+D for MacOS or Linux / Ctrl+Z for Windows to exit): ");
// doing the main calculation
// chacking the combined state and taking a decision
while (scanf("%d %d %d %d", &doorSensorState, &windowSensorState, &motionSensorState, &glassbreakSensorState) == 4)
{
// validating input
// The expression (variable & ~1) results in 0 only if 'variable' is 0 or 1.
// For any other positive number, it's non-zero.
// We combine all checks with a bitwise OR. If any sensor state is invalid,
// the flag will become non-zero.
invalidFlag = (doorSensorState & ~1) | (windowSensorState & ~1) | (motionSensorState & ~1) | (glassbreakSensorState & ~1);
// Combine the four sensor states into a single integer using bitwise operations.
// This creates a unique number from 0 to 15 for each possible combination.
// Bit 0: Door Sensor
// Bit 1: Window Sensor
// Bit 2: Motion Sensor
// Bit 3: Glass Break Sensor
combinedState = (glassbreakSensorState << 3) | (motionSensorState << 2) | (windowSensorState << 1) | doorSensorState;
// If the invalid_input_flag is non-zero, we add 16 to the state.
// This pushes it outside the 0-15 range and forces the 'default' case in the switch.
// We achieve this by multiplying the flag (which is > 0) by 16.
combinedState += invalidFlag * 16;
// printing the given state
printf("\n\nState : [Door : %d, Window : %d, Motion : %d, Glass Break : %d]\nState Id : %d",
doorSensorState, windowSensorState, motionSensorState, glassbreakSensorState, combinedState);
printf("\nSystem Action : ");
// taking decision based on combined state
// A single switch statement controls the program's behavior.
// It handles all 2^4 = 16 possible combinations of sensor states,
// ensuring exactly one action is taken for every scenario.
switch (combinedState)
{
case 0: // Binary: 0000
printf("System Idle. All sensors inactive.\n");
break;
case 1: // Binary: 0001
printf("Check front door camera.\n");
break;
case 2: // Binary: 0010
printf("Check window sensors.\n");
break;
case 3: // Binary: 0011
printf("Warning: Perimeter breach suspected. Check doors and windows.\n");
break;
case 4: // Binary: 0100
printf("Check interior cameras for movement.\n");
break;
case 5: // Binary: 0101
printf("Warning: Potential entry and movement detected. Check front door and interior. Ask for patrol.\n");
break;
case 6: // Binary: 0110
printf("Warning: Potential entry and movement detected. Check windows and interior. Ask for patrol.\n");
break;
case 7: // Binary: 0111
printf("Alert: High probability of unauthorized entry. Ask for patrol.\n");
break;
case 8: // Binary: 1000
printf("Alert: Glass break detected. High-priority event. Ask for patrol.\n");
break;
case 9: // Binary: 1001
printf("Severe Alert: Forced entry likely (door + glass). Activate Alarm and Contact authorities.\n");
break;
case 10: // Binary: 1010
printf("Severe Alert: Forced entry likely (window + glass). Activate Alarm and Contact authorities.\n");
break;
case 11: // Binary: 1011
printf("Intrusion Alert: Multiple perimeter breaches. Activate Alarm and Contact authorities.\n");
break;
case 12: // Binary: 1100
printf("Intrusion Alert: Confirmed interior presence after breach. Activate Alarm and Contact authorities.\n");
break;
case 13: // Binary: 1101
printf("INTRUSION CONFIRMED! Activate maximum response protocol. Activate Alarm and Contact authorities.\n");
break;
case 14: // Binary: 1110
printf("INTRUSION CONFIRMED! Activate maximum response protocol. Activate Alarm and Contact authorities.\n");
break;
case 15: // Binary: 1111
printf("CATASTROPHIC EVENT! ALL SENSORS TRIGGERED. ACTIVATE ALARM AND CONTACT COPS.\n");
break;
default:
// This case should not be reached with valid 0/1 input but is included for completeness.
printf("Error: Invalid sensor state detected.\n");
break;
}
// discarding extra characters (if any)
while (getchar() != '\n')
;
// asking for next set of input
printf("\nEnter next set of states: ");
}
printf("\nSecurity system shutting down.\n");
}/* Temperature of a city in fahrenheit degrees is input through
the keyboard. WAP to convert this temperature into Centigrade
degrees. */
/* Author - Amit Dutta, Date - 13 sep, 2025 */
/* Chapter 1; Page 19; Question NO.: F(a) */
#include<stdio.h>
int main() {
float f, c;
printf("Enter the temperature of city in Fahrenheit : ");
scanf("%f", &f);
// formula (F - 32) 5/9
c = ((f - 32) * 5) / 9;
printf("\nTemperature in centigrade : %f", c);
return 0;
}
/* The length and breadth of a rectangle and radius of a circle
are input through the keyboard. Write a program to calculate the
area and perimeter of the rectangle, and the area and circumference
of the circle. */
/* Author - Amit Dutta, Date - 16th SEP, 2025 */
/* Let Us C; Page - 19; Chap- 1; QNo.: F(b) */
#include <stdio.h>
#include <math.h>
int main()
{
double len, bre, r, area_r, per, area_c, cir;
printf("Enter the length and breadth of the rectangle : ");
scanf("%lf %lf", &len, &bre);
printf("Enter the Radius of the circle : ");
scanf("%lf", &r);
area_r = len * bre;
per = 2 * (len + bre);
area_c = M_PI * r * r;
cir = 2 * M_PI * r;
printf("\nArea of Rectangle : %lf"
"\nPerimeter of Rectangle : %lf"
"\nArea of Circle : %lf"
"\nCircumference of Circle : %lf",
area_r, per, area_c, cir);
return 0;
}
/* Paper of size AO has dimensions 1189 mm x 841 mm.
Each subsequent size A(n) is defined as A(n-1) cut in
half, parallel to its shorter sides. Thus, paper of
size A1 would have dimensions 841 mm x 594 mm. Write
a program to calculate and print paper sizes A0,
A1, A2, ... A8. */
/* Author - Amit Dutta, Date - 16th SEP, 2025 */
/* Let Us C; Page - 19; Chap- 1; QNo.: F(c) */
#include<stdio.h>
#include<math.h>
int main() {
double s_long = 1189.0, s_short = 841.0, temp;
int i;
printf("A0 Dimension : %g mm x %g mm", floor(s_long), floor(s_short));
for (i = 1; i <= 8; i++) {
temp = s_long;
s_long = s_short;
s_short = temp / 2;
printf("\nA%d Dimension : %g mm x %g mm", i, floor(s_long), floor(s_short));
}
return 0;
}
/* If a five digit number is input through the keyboard,
write a program to calculate the sum of it's digit.
(Hint : Use the modulus operator %) */
/* Author - Amit Dutta, Date - 28th SEP, 2025 */
/* Let Us C; Page - 37; Chap- 2; QNo.: G(a) */
#include <stdio.h>
int main()
{
int inp, result = 0, i, temp;
printf("Enter a five digit number : ");
scanf("%d", &inp);
if (inp < 10000 || inp > 99999)
{
printf("\nPlease enter a valid five digit number.");
return 1;
}
temp = inp;
for (i = 1; i <= 5; i++)
{
result = result + (inp % 10);
inp = inp / 10;
}
printf("\nSum of the digit '%d' is : %d", temp, result);
return 0;
}/* Write a program to recive Cartesian
co-ordinates (x, y) of a point and convert
them into Polar co-ordinates (r, phi)
Hint : r = sqrt (x^2 + y^2) and phi = tan^-1 (y/x) */
/* Author - Amit Dutta, Date - 28th SEP, 2025 */
/* Let Us C; Page - 37; Chap- 2; QNo.: G(b) */
#include <stdio.h>
#include <math.h>
int main()
{
double x, y, r, phi;
printf("Enter the Cartesian Co-Ordinates in this format 'x, y' : ");
scanf("%lf, %lf", &x, &y);
r = sqrt(pow(x, 2) + pow(y, 2));
phi = atan2(y, x);
printf("\nPolar Co-Ordinates are : (%g, %g Rad)", r, phi);
return 0;
}/* Write a program to receive values of latitude (L1, L2) and longitude
(G1, G2), in degrees, of two places on the earth and output the distance
(D) between them in nautical miles. The formula for distance in nautical
miles is :
D = 3963 cos^-1(sin L1 sin L2 + cos L1 cos L2 * cos(G2 - G1))
*/
/* Author - Amit Dutta, Date - 29th SEP, 2025 */
/* Let Us C, Chap - 2, Page - 37, Qn no.: G(c) */
#include <stdio.h>
#include <math.h>
int main()
{
double l1, l2, g1, g2, d;
printf("Enter the Latitude in 'L1, L2' format : ");
scanf("%lf, %lf", &l1, &l2);
printf("Enter the Longitude in 'G1, G2' format : ");
scanf("%lf, %lf", &g1, &g2);
// Converting degree to radian because function from math.h use radian not degree
l1 = l1 * (M_PI / 180);
l2 = l2 * (M_PI / 180);
g1 = g1 * (M_PI / 180);
g2 = g2 * (M_PI / 180);
d = 3963 * acos(sin(l1) * sin(l2) + cos(l1) * cos(l2) * cos(g2 - g1));
printf("Distance in nautical miles : %g", d);
return 0;
}/* Wind-chill factor is the felt air temperature on exposed skin due to wind.
The wind-chill temperature is always lower than the air temperature, and is
calculated as per the following formula.
wcf = 35.74 + 0.6215t + (0.4275t - 35.75) * v^0.16
Where t is temperature and v is wind velocity. Write a program to receive
values of t and v and calcualate wind-chill factor (wcf). */
/* Author - Amit Dutta, Date - 30th SEP, 2025 */
/* Let Us C, Chap - 2, Page - 37, Qn No.: G(d) */
#include <stdio.h>
#include <math.h>
int main()
{
double t, v, wcf;
printf("Enter the temperature and velociy of the wind : ");
scanf("%lf %lf", &t, &v);
wcf = 35.74 + (0.6215 * t) + (((0.4275 * t) - 35.75) * pow(v, 0.16));
printf("\nWind-chill factor (wcf) : %g", wcf);
return 0;
}/* If value of an angle is input through the keyboard,
write a program to print all its trigonometric ratios. */
/* Author - Amit Dutta, Date - 30th SEP, 2025 */
/* Let Us C, Chap - 2, Page - 37, Qn No.: G(e) */
#include <stdio.h>
#include <math.h>
int main()
{
double inp, rsin, rcos, rtan, rcosec, rsec, rcot;
printf("Enter the Angle in degree : ");
scanf("%lf", &inp);
inp = inp * (M_PI / 180); //changing degree to radian
rsin = sin(inp);
rcos = cos(inp);
rtan = tan(inp);
rcosec = 1 / rsin;
rsec = 1 / rcos;
rcot = 1 / rtan;
printf("\nTrigonometric ratios :-"
"\nsin = %g "
"\ncos = %g"
"\ntan = %g"
"\ncosec = %g"
"\nsec = %g"
"\ncot = %g",
rsin, rcos, rtan, rcosec, rsec, rcot);
return 0;
}/* Two numbers are input through the keyboard into two locations
C and D. Write a program to interchange the contents of C and D. */
/* Author - Amit Dutta, Date - 30th SEP, 2025 */
/* Let Us C, Chap - 2, Page - 37, Qn No.: G(d) */
#include <stdio.h>
int main()
{
double a, b;
printf("Enter the two number A and B : ");
scanf("%lf %lf", &a, &b);
printf("\nBefore Interchange : ");
printf("\nA = %g (Memory location = %p)", a, &a);
printf("\nB = %g (Memory location = %p)", b, &b);
a = a + b;
b = a - b;
a = a - b;
printf("\nAfter Interchange :");
printf("\nA = %g (Memory location = %p)", a, &a);
printf("\nB = %g (Memory location = %p)", b, &b);
return 0;
}/* A five-digit number is entered through the keyboard. Write a program
to obtain the reversed number and to etermine whether the original and reversed
numbers are equal or not. */
/* Author - Amit Dutta, Date - 1st OCT, 2025 */
/* Let Us C, Chap - 3, Page - 53, Qn No.: f(a) */
#include <stdio.h>
int main()
{
int num, rev, temp, i;
printf("Please enter the number : ");
scanf("%d", &num);
if (num < 10000 || num > 99999)
{
printf("\nPlease enter a five digit number.");
return 1;
}
temp = num;
for (i = 1; i <= 5; i++)
{
rev = (rev * 10) + num % 10;
num = num / 10;
}
printf("\nReverse of the Input number : %d", rev);
if (rev == temp)
printf("\nOriginal and reversed numbers are equal.");
else
printf("\nOrigianl and reversed numbers are not equal.");
return 0;
}/* If ages of Ram, Shyam and Ajay are input through the keyboard,
write a program to determine the youngest of the three. */
/* Author - Amit Dutta, Date - 1st OCT, 2025 */
/* Let Us C, Chap- 3, Page - 53, Qn No.: f(b) */
#include <stdio.h>
int main()
{
int ram, shyam, ajay;
printf("Please enter the age of Ram, Shyam and Ajay : ");
scanf("%d %d %d", &ram, ­am, &ajay);
if (ram == shyam || ram == ajay || shyam == ajay)
printf("\nThree must have different age.");
if (ram < shyam && ram < ajay)
printf("\nRam is the youngest. Age : %d", ram);
if (shyam < ram && shyam < ajay)
printf("\nShyam is the youngest. Age : %d", shyam);
if (ajay < ram && ajay < shyam)
printf("\nAjay is the youngest. Age : %d", ajay);
return 0;
}/* Write a program to check whether a triangle is valid or not,
if three angles of the triangle are entered through the keyboard.
A triangle is valid if the sum of all the three angles is equal to 180 degrees. */
/* Author - Amit Dutta, Date - 1st OCT, 2025 */
/* Let Us C, Chap- 3, Page - 53, Qn No.: f(c) */
#include <stdio.h>
int main()
{
double angle1, angle2, angle3, sum;
printf("Enter the value of the three angle of the triangle : ");
scanf("%lf %lf %lf", &angle1, &angle2, &angle3);
sum = angle1 + angle2 + angle3;
if (sum == 180.0)
printf("\nThis Triangle is a valid one.");
else
printf("\nThis Triangle is not valid. Sum of the angles : %g", sum);
return 0;
}/* Write a program to find the absolute value
of a number entered through the keyboard. */
/* Author - Amit Dutta, Date - 1st OCT, 2025 */
/* Let Us C, Chap- 3, Page - 53, Qn No.: f(d) */
#include <stdio.h>
#include <math.h>
int main()
{
double num;
printf("Enter the number : ");
scanf("%lf", &num);
num = abs(num);
printf("\nAbsolute value of the input is : %g", num);
return 0;
}/* Given the length and breadth of a rectangle, write a program to find
whether the area of the rectangle is greater than it's perimeter.
For example, the area of the rectangle with length = 5 and breadth = 4
is greater than its perimeter. */
/* Author - Amit Dutta, Date - 1st OCT, 2025 */
/* Let Us C, Chap- 3, Page - 53, Qn No.: f(e) */
#include <stdio.h>
int main()
{
double len, bre, area, peri;
printf("Enter the length and breadth of the rectangle : ");
scanf("%lf %lf", &len, &bre);
area = len * bre;
peri = 2 * (len + bre);
if (area > peri)
printf("\nThe area of the rectangle is greater than it's perimeter.");
else if (area < peri)
printf("\nThe area of the rectangle is lower than it's perimeter.");
else
printf("\nThe area of the rectangle is same as it's perimeter.");
return 0;
}/* Given three points (x1, y1), (x2, y2), and (x3, y3),
write a program to check if the three poins fall on one straight line. */
/* Author - Amit Dutta, Date - 1st OCT, 2025 */
/* Let Us C, Chap- 3, Page - 53, Qn No.: f(f) */
#include <stdio.h>
#include <math.h>
#define EPSILON 0.0001
// Define a small tolerance value (EPSILON) for safe floating-point comparison
// This is critical because of minor rounding errors in computer arithmetic.
int main()
{
double x1, x2, x3, y1, y2, y3, area;
printf("Enter the point A(x1, y1) : ");
scanf("%lf %lf", &x1, &y1);
printf("Enter the point B(x2, y2) : ");
scanf("%lf %lf", &x2, &y2);
printf("Enter the point C(x3, y3) : ");
scanf("%lf %lf", &x3, &y3);
area = 0.5 * ((x1 * (y2 - y3)) + (x2 * (y3 - y1)) + (x3 * (y1 - y2)));
if (fabs(area) < EPSILON) // abs() for integer, fabs() for float, double
printf("\nA(%g, %g), B(%g, %g) and C(%g, %g) points fall on one straight line.", x1, y1, x2, y2, x3, y3);
else
printf("\nA(%g, %g), B(%g, %g) and C(%g, %g) points doesn't fall on one straight line.", x1, y1, x2, y2, x3, y3);
return 0;
}/* Given the coordiantes (x, y) of center of a circle and its radius,
write a program that will determine whether a point lies inside the circle,
on the circle or outside the circle. (Hint : Use sqrt() and pow() functions.) */
/* Author - Amit Dutta, Date - 1st OCT, 2025 */
/* Let Us C, Chap- 3, Page - 53, Qn No.: f(g) */
#include <stdio.h>
#include <math.h>
// Define a small tolerance value (EPSILON) for reliable floating-point comparison
#define EPSILON 0.0001
int main()
{
double h, k;
double R;
double x, y;
double distance_sq;
printf("Enter the center coordinates (h, k) : ");
scanf("%lf %lf", &h, &k);
printf("Enter the radius (R) : ");
scanf("%lf", &R);
printf("Enter the point P coordinates (x, y) : ");
scanf("%lf %lf", &x, &y);
distance_sq = pow(x - h, 2) + pow(y - k, 2);
double radius_sq = R * R;
// Case 1: On the circle (D^2 = R^2) - Use EPSILON for safety!
if (fabs(distance_sq - radius_sq) < EPSILON)
{
printf("The point P(%g, %g) lies ON THE CIRCLE.\n", x, y);
}
// Case 2: Inside the circle (D^2 < R^2)
else if (distance_sq < radius_sq)
{
printf("The point P(%g, %g) lies INSIDE THE CIRCLE.\n", x, y);
}
// Case 3: Outside the circle (D^2 > R^2)
else
{
printf("The point P(%g, %g) lies OUTSIDE THE CIRCLE.\n", x, y);
}
return 0;
}/* Given a point (x, y), write a program to find out if it lies on X-axis, Y-axis or origin. */
/* Author - Amit Dutta, Date - 1st OCT, 2025 */
/* Let Us C, Chap- 3, Page - 53, Qn No.: f(h) */
#include <stdio.h>
#include <math.h>
#define EPSILON 0.00001
int main()
{
double x, y;
printf("Enter the point P(x, y) : ");
scanf("%lf %lf", &x, &y);
if (fabs(x) < EPSILON && fabs(y) < EPSILON)
printf("\nPoint P(%g, %g) lies on the origin.", x, y);
else if (fabs(x) < EPSILON)
printf("\nPoint P(%g, %g) lies on the Y-Axis.", x, y);
else if (fabs(y) < EPSILON)
printf("\nPoint P(%G, %g) lies on the X-Axis.", x, y);
else
printf("\nThe point P(%g, %g) lies in a QUADRANT (not on an axis or the origin).", x, y);
return 0;
}/* According to Gregorian calender, it was Monday on the date 01/01/01.
Write a program to find out what is the day on 1st January of any input year. */
/* Author - Amit Dutta, Date - 1st OCT, 2025 */
/* Let Us C, Chap- 3, Page - 53, Qn No.: f(i) */
#include <stdio.h>
/**
* @brief Determines if a given year is a leap year.
* * The rule: A year is a leap year if it is divisible by 4, UNLESS it is
* divisible by 100 but NOT by 400.
* * @param year The year to check.
* @return 1 if it is a leap year, 0 otherwise.
*/
int is_leap(int year) {
// Check if divisible by 400 OR (divisible by 4 AND not divisible by 100)
if ((year % 400 == 0) || (year % 4 == 0 && year % 100 != 0)) {
return 1;
}
return 0;
}
/**
* @brief Calculates the day of the week for January 1st of the given year.
* * The base date is 01/01/01, which was a Monday (index 1).
* * Day Mapping: 0:Sunday, 1:Monday, 2:Tuesday, 3:Wednesday, 4:Thursday, 5:Friday, 6:Saturday
*/
int main() {
long long year; // Use long long for year input if years far in the future/past are tested
int i;
long long total_days = 0;
int day_index;
// Day names array for output
const char *day_names[] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
printf("Enter the year (e.g., 2025): ");
if (scanf("%lld", &year) != 1 || year < 1) {
printf("Invalid year input. Please enter a positive integer year (>= 1).\n");
return 1;
}
// --- Core Logic: Calculate Total Days ---
// We only need to consider the years that have *passed* before the target year.
// So, we count days from the end of year 0 up to the end of year (year - 1).
int years_passed = year - 1;
// 1. Calculate the number of leap days up to the end of year (year - 1)
// Formula based on Gregorian calendar rules for years Y-1:
// (Y-1)/4 - (Y-1)/100 + (Y-1)/400
long long leap_years = years_passed / 4 - years_passed / 100 + years_passed / 400;
// 2. Total days = (Number of years * 365) + (Number of leap years)
// Note: The loop method (below) is more intuitive but the formula is faster.
// We will use the direct formula for efficiency.
total_days = years_passed * 365 + leap_years;
// --- Alternate Loop Method (for conceptual simplicity) ---
/*
for (i = 1; i < year; i++) {
total_days += 365;
if (is_leap(i)) {
total_days += 1; // Add 1 for the leap day
}
}
*/
// --- Determine the Day of the Week ---
// Since 01/01/01 was Monday (index 1), we use the following setup:
// Index 1 corresponds to Monday.
// The calculation gives the number of days *past* the Monday start (01/01/01).
// The modulo operation gives the remainder (0-6).
// 0 days elapsed (Year 1): total_days=0. (0 + 1) % 7 = 1 (Monday). Correct.
// 365 days elapsed (Year 2): total_days=365. (365 + 1) % 7 = 2 (Tuesday). Correct. (365 mod 7 = 1, 1+1 = 2)
day_index = (total_days + 1) % 7;
// Correct the Day Index to match the array (0:Sun, 1:Mon, ..., 6:Sat)
// The +1 adjusts for the Monday starting point (index 1).
printf("\nOn January 1st, %lld, the day was: **%s**.\n", year, day_names[day_index]);
return 0;
}/* According to Gregorian calender, it was Monday on the date 01/01/01.
if any year is input through the keyboard write a program to find out
what is the day on 1st January of this year. */
/* Author - Amit Dutta, Date - 1st OCT, 2025 */
/* Let Us C, Chap- 3, Page - 53, Qn No.: f(i) */
#include <stdio.h>
int is_leap(int year) {
if ((year % 400 == 0) || (year % 4 == 0 && year % 100 != 0)) {
return 1;
}
return 0;
}
int main() {
long long year; // long long for year input if years far in the future/past are tested
int i;
long long total_days = 0;
int day_index;
// Day names array for output
const char *day_names[] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
printf("Enter the year (e.g., 2025): ");
if (scanf("%lld", &year) != 1 || year < 1) {
printf("Invalid year input. Please enter a positive integer year (>= 1).\n");
return 1;
}
int years_passed = year - 1;
long long leap_years = years_passed / 4 - years_passed / 100 + years_passed / 400;
total_days = years_passed * 365 + leap_years;
day_index = (total_days + 1) % 7;
printf("\nOn January 1st, %lld, the day was: %s.\n", year, day_names[day_index]);
return 0;
}/* If the length of three sides of a triangle are entered through the
keyboard, write a program to check whether the triangle is an isosceles,
an equilateral, a scalene or a right-angled triangle. */
/* Author - Amit Dutta, Date - 3rd OCT, 2025 */
/* Let Us C, Chap- 4, Page - 71, Qn No.: D(a) */
#include <stdio.h>
#include <math.h>
#define EPSILON 0.000001
/* EPSILON is used to compare double values for approximate equality,
mitigating floating-point precision errors. */
int main()
{
double side1, side2, side3;
printf("Please enter the length of three side of the triangle : ");
scanf("%lf %lf %lf", &side1, &side2, &side3);
if (side1 < 1 || side2 < 1 || side3 < 1)
{
printf("\nLength of a side of triangle should be a positive integer.");
return 1;
}
if (side1 + side2 < side3 || side1 + side3 < side2 || side2 + side3 < side1)
{
printf("\nEntered triangle is not VALID.");
return 1;
}
// isosceles check
if (side1 == side2 || side2 == side3 || side3 == side1)
printf("\nEntered triangle is a ISOSCELES triangle.");
else
printf("\nEntered triangle is NOT a ISOSCELES triangle.");
// equilateral check
if (side1 == side2 && side2 == side3)
printf("\nEntered triangle is a EQUILATERAL triangle.");
else
printf("\nEntered triangle is NOT a EQUILATERAL triangle.");
// scalene check
if (side1 != side2 && side2 != side3)
printf("\nEntered triangle is a SCALENE triangle.");
else
printf("\nEntered triangle is NOT a SCALENE triangle.");
// right-angle check
if (fabs(((side1 * side1) + (side2 * side2)) - (side3 * side3)) < EPSILON ||
fabs(((side2 * side2) + (side3 * side3)) - (side1 * side1)) < EPSILON ||
fabs(((side3 * side3) + (side1 * side1)) - (side2 * side2)) < EPSILON)
printf("\nEntered triangle is a RIGHT-ANGLED triangle.");
else
printf("\nEntered triangle is NOT a RIGHT-ANGLED triangle.");
return 0;
}/* In digital world colors are specified in Red-Green-Blue (RGB) format,
with values of R, G, B varying on an integer scale from 0 to 255. In print
publishing the colors are mentioned in Cyan-Magenta-Yellow-Black (CMYK) format,
with values of C, M, Y, and K varying on a real scale from 0.0 to 1.0.
Write a program that converts RGB color to CMYK color as per the following formulae:
White = Max(Red/255, Green/255, Blue/255)
Cyan = (White-Red/255) / White
Magenta = (White-Green/255) / White
Yellow = (White-Blue/255) / White
Black = 1 - White
Note that if the RGB values are all 0, then the CMY values are all 0 and the K value is 1. */
/* Author - Amit Dutta, Date - 4th OCT, 2025 */
/* Let Us C, Chap- 4, Page - 71, Qn No.: D(b) */
#include <stdio.h>
// declaring function
double get_white(double red, double green, double blue)
{
double max;
max = red / 255;
if (max < (green / 255))
max = green / 255;
if (max < (blue / 255))
max = blue / 255;
return max;
}
int main()
{
double r, g, b, w, c = 0, m = 0, y = 0, k = 0;
printf("Enter the RGB color code in 'R G B' format : ");
scanf("%lf %lf %lf", &r, &g, &b);
// checking for invalid input (negetive input)
if (r < 0 || g < 0 || b < 0)
{
printf("\nRGB color code can not be a negetive number.");
return 1;
}
// checking for invalid input (out of range color code)
if (r > 255 || g > 255 || b > 255)
{
printf("\nRGB color code can be maximum (255, 255, 255).");
return 1;
}
// converting RGB color code to CMYK color code
if (r == 0 && g == 0 && b == 0)
k = 1;
else
{
w = get_white(r, g, b);
c = (w - (r / 255)) / w;
m = (w - (g / 255)) / w;
y = (w - (b / 255)) / w;
k = 1 - w;
}
printf("\nRGB color (%g, %g, %g) equivalent to CMYK color (%g, %g, %g, %g).", r, g, b, c, m, y, k);
return 0;
}/* A certain grade of steel is graded according to the following conditions:
(i) Hardness must be greater than 50
(ii) Carbon content must be less than 0.7
(iii) Tensile strength must be greater than 5600
The grades are as follows:
Grade is 10 if all three conditions are met
Grade is 9 if conditions (i) and (ii) are met
Grade is 8 if conditions (ii) and (iii) are met
Grade is 7 if conditions (i) and (iii) are met
Grade is 6 if only one condition is met
Grade is 5 if none of the conditions are met
Write a program, which will require the user to give values of hardness,
carbon content and tensile strength of the steel under consideration and output
the grade of the steel. */
/* Author - Amit Dutta, Date - 4th OCT, 2025 */
/* Let Us C, Chap- 4, Page - 71, Qn No.: D(c) */
#include <stdio.h>
int main()
{
double hardness, carbon_content, tensile_strength;
printf("Enter the details of the steel below - \n");
printf("1. Hardness : ");
scanf("%lf", &hardness);
printf("2. Carbon Content : ");
scanf("%lf", &carbon_content);
printf("3. Tensile Strength : ");
scanf("%lf", &tensile_strength);
// storing how many conditions are met as boolean result
int condition_met, condition1, condition2, condition3;
condition1 = hardness > 50;
condition2 = carbon_content < 0.7;
condition3 = tensile_strength > 5600;
condition_met = condition1 + condition2 + condition3;
// now grading according the result
int grade;
if (condition_met == 3)
grade = 10;
else if (condition_met == 2)
{
if (condition1 && condition2)
grade = 9;
else if (condition2 && condition3)
grade = 8;
else if (condition1 && condition3)
grade = 7;
}
else if (condition_met == 1)
grade = 6;
else
grade = 5;
// printing the result
printf("\n------------- Result -------------");
printf("\n1. Hardness : Condition %s", condition1 ? "MET" : "DID NOT MET");
printf("\n2. Carbon Content : Condition %s", condition2 ? "MET" : "DID NOT MET");
printf("\n3. Tensile Strength : Condition %s", condition3 ? "MET" : "DID NOT MET");
printf("\nTotal Condition Met : %d", condition_met);
printf("\n\nGrade : %d\n\n", grade);
return 0;
}
/* I did not used this long variable names. I used very short just the first letter of the word.
After writting the whole program, I just renamed the valiables. This is possible in Visual Stdio Code. *//* The Body Mass Index (BMI) is defined as ratio of weight of the
person (in Kilograms) to square of the height (in meters).
Write a program that receives weight and height, calculate the BMI, and reports
the BMI catagory as per the following table.
BMI Catagory BMI
Starvation < 15
Anorexic 15.1 to 17.5
Underweight 17.6 to 18.5
Ideal 18.6 to 24.9
Overweight 25 to 25.9
Obese 30 to 39.9
Morbidly Obese >= 40
*/
/* Author - Amit Dutta, Date - 4th OCT, 2025 */
/* Let Us C, Chap- 4, Page - 72, Qn No.: D(d) */
#include <stdio.h>
int main()
{
double weight, height, bmi;
printf("Enter your Weight (in Kilograms) and Height (in Meters) : ");
scanf("%lf %lf", &weight, &height);
bmi = weight / (height * height);
printf("\nCalculated BMI : %g", bmi);
if (bmi < 15)
printf("\nBMI Catagory : Starvation");
else if (bmi >= 15.1 && bmi <= 17.5)
printf("\nBMI Catagory : Anorexic");
else if (bmi >= 17.6 && bmi <= 18.5)
printf("\nBMI Catagory : Underweight");
else if (bmi >= 18.6 && bmi <= 24.9)
printf("\nBMI Catagory : Ideal");
else if (bmi >= 25 && bmi <= 25.9)
printf("\nBMI Catagory : Overweight");
else if (bmi >= 30 && bmi <= 39.9)
printf("\nBMI Catagory : Obese");
else if (bmi >= 40)
printf("\nBMI Catagory : Morbidly Obese");
else
printf("\nBMI Catagory : Unclassified");
return 0;
}/* Using conditional operators determine :
(1) Whether the character entered through the keyboard is a
lower case alphabet or not.
(2) Whether a character entered through the keyboard is a special
symbol or not. */
/* Author - Amit Dutta, Date - 5th OCT, 2025 */
/* Let Us C, Chap- 4, Page - 72, Qn No.: E(a) */
#include <stdio.h>
int main()
{
char inp;
printf("Enter the character : ");
scanf("%c", &inp);
printf("\nInput Character '%c' is %s a LOWER CASE ALPHABET.", inp,
(inp >= 'a' && inp <= 'z') ? "" : "NOT");
printf("\nInput Character '%c' is %s a SPECIAL SYMBOL.", inp,
(inp >= 'a' && inp <= 'z' || inp >= 'A' && inp <= 'Z'
|| inp >= '0' && inp <= '9') ? "NOT" : "");
return 0;
}/* Write a program using conditional operators to determine whether
a year entered through the keyboard is a leap year or not. */
/* Author - Amit Dutta, Date - 5th OCT, 2025 */
/* Let Us C, Chap- 4, Page - 72, Qn No.: E(b) */
#include <stdio.h>
int main()
{
int year;
printf("Enter the year : ");
scanf("%d", &year);
printf("\nYear %d is %s a Leapyear.", year, (year % 400 == 0 || year % 4 == 0 && year % 100 != 0) ? "" : "NOT");
return 0;
}/* Write a program to find the greates of the three numbers entered
through the keyboard. Use conditional operators. */
/* Author - Amit Dutta, Date - 6th OCT, 2025 */
/* Let Us C, Chap- 4, Page - 72, Qn No.: E(c) */
#include <stdio.h>
int main()
{
double num1, num2, num3, max;
printf("Enter three number : ");
scanf("%lf %lf %lf", &num1, &num2, &num3);
printf("\nGreatest of the three number '%g', '%g' and '%g' is : '%g'", num1, num2, num3,
(num1 > num2 && num1 > num3) ? num1 : ((num2 > num1 && num2 > num3) ? num2 : num3));
return 0;
}/* Write a program to recieve value of an angle in degreesand check
whether sum of squares of sine and cosine of this angle is equal to 1. */
/* Author - Amit Dutta, Date - 6th OCT, 2025 */
/* Let Us C, Chap- 4, Page - 73, Qn No.: E(d) */
#include <stdio.h>
#include <math.h>
#define EPSILON 0.0000001
int main()
{
double angle, result;
printf("Enter the angle value in degree : ");
// checking if the input is other than number.
if(scanf("%lf", &angle) != 1) {
printf("\nPlease enter a number.");
return 1;
}
angle = angle * (M_PI / 180); // converting degree to radian
result = pow(sin(angle), 2) + pow(cos(angle), 2);
(fabs(result - 1.0) < EPSILON) ?
printf("\nsum of squares of sine and cosine of this angle is equal to 1.") :
printf("\nsum of squares of sine and cosine of this angle is NOT equal to 1.");
return 0;
}/* Rewrite the folowing program using conditional operations
#include<stdio.h>
int main()
{
float sal;
printf("Enter the salary");
scanf("%f", &sal);
if(sal >= 25000 && sal <= 40000)
printf("Manager\n");
else
if(sal >= 15000 && sal < 25000)
printf("Accountant\n");
else
printf("Clerk\n");
return 0;
}
*/
/* Author - Amit Dutta, Date - 6th OCT, 2025 */
/* Let Us C, Chap- 4, Page - 73, Qn No.: E(e) */
#include <stdio.h>
int main()
{
float sal;
printf("Enter the salary");
scanf("%f", &sal);
(sal >= 25000 && sal <= 40000) ? printf("Manager\n") :
((sal >= 15000 && sal < 25000) ? printf("Accountant\n") : printf("Clerk\n"));
return 0;
}/* Write a program to print all the ASCII values and their equivalent
characters using a while loop. The ASCII may vary from 0 to 255. */
/* Author - Amit Dutta, Date - 7th OCT, 2025 */
/* Let Us C, Chap- 5, Page - 87, Qn No.: B(a) */
#include <stdio.h>
int main()
{
int i = 0;
printf("ASCII Value\tCharacter");
printf("\n-----------\t---------\n");
while (i <= 255)
{
printf("%d.\t%c\n\n", i, i);
i++;
}
return 0;
}/* Write a program to print out all Armstrong numbers between 100
and 500. If sum of cubes of each digit of the number is equal to the
number itself, then the number is called an Armstrong number. For
example, 153 = (1 * 1 * 1) + (5 * 5 * 5) + (3 * 3 * 3) */
/* Author - Amit Dutta, Date - 7th OCT, 2025 */
/* Let Us C, Chap- 5, Page - 87, Qn No.: B(b) */
#include <stdio.h>
#include <math.h>
int main()
{
int num = 100, temp1, temp2, res;
printf("Armstrong numbers between 100 and 500 :");
while (num <= 500)
{
temp1 = num;
res = 0;
while (temp1 != 0)
{
temp2 = temp1 % 10;
res = res + pow(temp2, 3);
temp1 = temp1 / 10;
}
if (num == res)
printf(" %d", num);
num++;
}
return 0;
}/* Write a program for a matchstick game being played between the
computer and a user. Your program should ensure that the computer
always wins. Rules for the game are as follows :
- There are 21 matchsticks.
- The computer asks the player to pick 1, 2, 3, or 4 matchsticks.
- After the person picks, the computer does its picking.
- Whoever is forced to pick up the last matchstick loses the game.
*/
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
/* Let Us C, Chap- 5, Page - 87, Qn No.: B(c) */
/* My Plan: The total number of matchsticks is 21. To guarantee a win,
the computer ensures that after its turn, the number of remaining
matchsticks is always a multiple of 5 plus 1 (i.e., 16, 11, 6, 1).
This is achieved by making the sum of the player's pick and the
computer's pick equal to 5 in each round. This forces the player
to pick the final matchstick. */
#include <stdio.h>
int main()
{
int remaining_matchsticks = 21, player_pick, computer_pick;
printf(" --- Matchstick Game ---\n");
printf("Rules: There are 21 matchsticks. You can pick 1, 2, 3, or 4.\n");
printf("Whoever is forced to pick the last matchstick loses the game.\n");
while (remaining_matchsticks > 1)
{
// game start
printf("\n--------------------------");
printf("\nRemaining Matchsticks : %d", remaining_matchsticks);
// player pick and checking input is valid or not
printf("\nYour turn: Pick 1, 2, 3, or 4 matchsticks: ");
if (scanf("%d", &player_pick) != 1)
{
printf("\n\tPlease enter a number.");
while (getchar() != '\n')
;
continue;
}
// checking player pick is valid or not
if (player_pick < 1 || player_pick > 4)
{
printf("\n\tPlease enter a number among 1, 2, 3 and 4.");
while (getchar() != '\n')
;
continue;
}
if (player_pick > remaining_matchsticks)
{
printf("\nInvalid choice! There are not enough matchsticks left.");
while (getchar() != '\n')
;
continue;
}
// computer_picks
computer_pick = 5 - player_pick;
printf("\ncomputer_picks : %d", computer_pick);
// remaining matchsticks
remaining_matchsticks = remaining_matchsticks - (player_pick + computer_pick);
}
// game over
printf("\n----------------------------------\n");
printf("Only 1 matchstick is left.\n");
printf("You are forced to pick the last matchstick. You lose!\n");
printf("The computer wins.\n");
return 0;
}/* Write a program to enter numbers till the user wants. At the end it
should display the count of positive, negative and zeros entered. */
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
/* Let Us C, Chap- 5, Page - 87, Qn No.: B(d) */
/*
* DETAILED PROGRAM PLAN:
* 1. INITIALIZATION: Set three counters (positive_count, negative_count, zero_count) to zero.
* 2. INPUT LOOP: Start an infinite loop to continuously request user input.
* 3. READ INPUT: Use fgets() to read the user's input as a generic string (char array).
* This allows the program to accept multi-digit numbers (e.g., "-500") or the command ('n').
* 4. TERMINATION CHECK: Immediately check if the input string is exactly "n" using strcmp().
* If true, the user wants to quit, so break the loop.
* 5. VALIDATION & CONVERSION: If the input is not "n", use sscanf() to safely attempt to convert
* the string into an integer.
* 6. COUNTING LOGIC: If sscanf() successfully reads an integer (sscanf returns 1):
* - If the number is > 0, increment positive_count.
* - If the number is < 0, increment negative_count.
* - If the number is == 0, increment zero_count.
* 7. ERROR HANDLING: If the input is neither "n" nor a valid number (sscanf returns 0),
* inform the user of invalid input and continue the loop.
* 8. FINAL DISPLAY: After the loop terminates, print the final totals for positive, negative, and zero counts.
*/
#include <stdio.h>
#include <stdlib.h> // for strtol
#include <string.h> // for strcmp
// Maximum size of the input line
#define MAX_INPUT_LEN 15
int main() {
// Initialize counters
int positive_count = 0;
int negative_count = 0;
int zero_count = 0;
// Buffer to store the user's input as a string (e.g., "123", "-50", or "n")
char input_buffer[MAX_INPUT_LEN];
int number;
printf("--- Number Analyzer ---\n");
printf("Enter numbers one by one. Type 'n' and press Enter to finish.\n\n");
// Loop until the user enters 'n'
while (1) {
printf("Enter number or 'n': ");
// Read the entire line of input into the buffer
if (fgets(input_buffer, MAX_INPUT_LEN, stdin) == NULL) {
// Handle EOF (end of file) or reading error
break;
}
// Remove the trailing newline character from the input_buffer
// The last character will be '\n' if the input was shorter than MAX_INPUT_LEN
size_t len = strlen(input_buffer);
if (len > 0 && input_buffer[len - 1] == '\n') {
input_buffer[len - 1] = '\0';
}
// 1. Check for the termination condition
if (strcmp(input_buffer, "n") == 0) {
printf("\n'n' received. Stopping input...\n");
break; // Exit the while loop
}
// 2. Attempt to convert the input string to an integer
// sscanf attempts to read the string according to the format "%d" (decimal integer)
// It returns 1 if a number was successfully read.
int conversions = sscanf(input_buffer, "%d", &number);
if (conversions == 1) {
// Conversion was successful, now check the number's sign
if (number > 0) {
positive_count++;
} else if (number < 0) {
negative_count++;
} else {
zero_count++;
}
printf(" -> Number recorded: %d\n", number);
} else {
// Conversion failed. The input was neither 'n' nor a valid integer.
printf(" -> Invalid input. Please enter a valid number or 'n'.\n");
}
}
// Display the final results
printf("\n====================================\n");
printf(" Analysis Complete\n");
printf("====================================\n");
printf("Positive numbers entered: %d\n", positive_count);
printf("Negative numbers entered: %d\n", negative_count);
printf("Zeroes entered: %d\n", zero_count);
printf("Total numbers recorded: %d\n", positive_count + negative_count + zero_count);
printf("====================================\n");
return 0;
}/* Write a program to enter numbers till the user wants. At the end it
should display the count of positive, negative and zeros entered. */
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
/* Let Us C, Chap- 5, Page - 87, Qn No.: B(d) */
#include <stdio.h>
int main()
{
int choice = 1, num, positive_count = 0, negative_count = 0, zero_count = 0;
while (choice == 1)
{
printf("\nEnter the number (Type any character and press Enter to finish.) : ");
choice = scanf("%d", &num); // Checking whether the user has input any characters
if (choice == 1)
{
printf("Number recorded : %d", num);
if (num < 0)
negative_count++;
else if (num > 0)
positive_count++;
else if (num == 0)
zero_count++;
}
else
{
// If the user inputs any characters, then choice = 0, it means he doesn't want to give any more input;
choice = 0;
printf("\nCharacter received. Stopping input...\n");
}
}
// Display the final results
printf("\n====================================\n");
printf(" Analysis Complete\n");
printf("====================================\n");
printf("Positive numbers entered: %d\n", positive_count);
printf("Negative numbers entered: %d\n", negative_count);
printf("Zeroes entered: %d\n", zero_count);
printf("Total numbers recorded: %d\n", positive_count + negative_count + zero_count);
printf("====================================\n");
}/* Write a program to recieve an integer and find its octal equivalent.
(Hint : To obtain octal equivalent of an integer, Divide it continuously
by 8 till dividend does not become zero, then write the remainders
obtained in reverse derection.) */
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
/* Let Us C, Chap- 5, Page - 87, Qn No.: B(e) */
// using array
#include <stdio.h>
int main()
{
int octal[20], decimal, index = 0, temp, rem;
printf("Enter the decimal number : ");
scanf("%d", &decimal);
temp = decimal;
while (temp != 0)
{
rem = temp % 8;
temp = temp / 8;
octal[index] = rem;
index++;
}
printf("\nDeciaml %d to octal : ", decimal);
while ((index - 1) >= 0)
{
printf("%d", octal[index - 1]);
index--;
}
return 0;
}/* Write a program to find the range of a set of numbers entered
through the keyboard. Range is the difference between the smallest
and biggest number in the list. */
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
/* Let Us C, Chap- 5, Page - 87, Qn No.: B(f) */
#include <stdio.h>
int main()
{
int choice = 1, set_of_numbers[30], num, index = -1;
while (choice == 1)
{
printf("\nEnter the number (Type any character and press Enter to finish.) : ");
choice = scanf("%d", &num); // Checking whether the user has input any characters
if (choice != 1)
{
// If the user inputs any characters, then choice = 0, it means he doesn't want to give any more input;
choice = 0;
printf("\nCharacter received. Stopping input...\n");
break;
}
index++;
set_of_numbers[index] = num;
}
int max = set_of_numbers[0], min = set_of_numbers[0];
while (index >= 0)
{
if (max < set_of_numbers[index])
max = set_of_numbers[index];
if (min > set_of_numbers[index])
min = set_of_numbers[index];
index--;
}
int range = max - min;
printf("\nBiggest number in the set : %d", max);
printf("\nSmallest number in the set : %d", min);
printf("\nRange : %d", range);
return 0;
}/* Consider a currency system in which there are notes of six denominations,
namely, Rs. 1, Rs. 2, rs. 5, Rs. 10, Rs. 50, Rs. 100. If a sum
of Rs. N is entered through the keyboard, Write a program to compute
the smallest number of notes that will combine to give Rs. N. */
/* Author - Amit Dutta, Date - 29th SEP, 2025 */
/* Let Us C, Chap - 2, Page - 22, Problem 2.3 */
#include <stdio.h>
int main()
{
int n, nonotes, temp;
printf("Enter the amount : ");
scanf("%d", &n);
if (n < 1)
{
printf("\nAmount should be a positive integer.");
return 1;
}
temp = n;
nonotes = n / 100;
n = n % 100;
nonotes = nonotes + (n / 50);
n = n % 50;
nonotes = nonotes + (n / 10);
n = n % 10;
nonotes = nonotes + (n / 5);
n = n % 5;
nonotes = nonotes + (n / 2);
n = n % 2;
nonotes = nonotes + n;
printf("\nthe smallest number of notes that will combine to give Rs. %d : %d", temp, nonotes);
return 0;
}/* A year is entered through the keyboard, write a program to
determine whether the year is leap or not. Use the logical operators
&& and || . */
/* Author - Amit Dutta, Date - 02th OCT, 2025 */
/* Let Us C, Chap - 4, Page - 64, Problem 4.1 */
#include <stdio.h>
int main()
{
int year;
printf("Enter year : ");
scanf("%d", &year);
if (year % 4 == 0 && year & 100 != 0 || year % 400 == 0)
printf("\nYear %d is a leapyear.", year);
else
printf("\nYear %d is not a leapyear.", year);
return 0;
}/* If a character is entered through the keyboard, Write a program
to determine whether the character is a capital letter, a small case letter,
a digit or a speacial symbol.
The following table shows the range of ASCII values for various characters :
Characters ASCII Values
A - Z 65 - 90
a - z 97 - 122
0 - 9 48 - 57
special symbols 0 - 47, 58 - 64, 91 - 96, 123 - 127
*/
/* Author - Amit Dutta, Date - 02th OCT, 2025 */
/* Let Us C, Chap - 4, Page - 65, Problem 4.2 */
#include <stdio.h>
int main()
{
char inp;
printf("Enter one character : ");
scanf(" %c", &inp);
if (inp >= 64 && inp <= 90)
printf("\nInput '%c' is a CAPITAL LETTER.", inp);
if (inp >= 97 && inp <= 122)
printf("\nInput '%c' is a SMALL CASE LETTER.", inp);
if (inp >= 48 && inp <= 57)
printf("\nInput '%c' is a DIGIT.", inp);
if (inp >= 0 && inp <= 47 || inp >= 58 && inp <= 64
|| inp >= 91 && inp <= 96 || inp >= 123 && inp <= 127)
printf("\nInput '%c' is a SPECIAL SYMBOL.", inp);
return 0;
}/* If the lengths of three sides of a triangle are entered through the
keyboard, write a program to check whether the triangle is valid or not.
The triangle is valid if the sum of two sides is greater that the largest
of the three sides. */
/* Author - Amit Dutta, Date - 02th OCT, 2025 */
/* Let Us C, Chap - 4, Page - 66, Problem 4.3 */
#include <stdio.h>
int main()
{
double side1, side2, side3;
printf("Enter the length of side1, side2 and side3 of the triangle : ");
scanf("%lf %lf %lf", &side1, &side2, &side3);
if (side1 <= 0 || side2 <= 0 || side3 <= 0)
{
printf("\nTriangle sides must be positive.\n");
return 1;
}
if ((side1 + side2 > side3) && (side1 + side3 > side2) && (side2 + side3 > side1))
// Triangle Inequality Theorem
printf("\nThis triangle is valid.");
else
printf("\nThis triangle is not valid.");
return 0;
}/* Write a program to calculate overtime pay of 10 employees. Overtime is
paid at the rate of Rs. 120.00 per hour for every hour worked above 40
hours. Assume that employees do not work for fractional part of an hour. */
/* ONLY WHILE LOOP ALLOWED */
/* Author - Amit Dutta, Date - 07th OCT, 2025 */
/* Let Us C, Chap - 5, Page - 83, Problem 5.1 */
#include <stdio.h>
#include <conio.h>
int main()
{
int working_hour, i = 1;
double pay;
while (i <= 10)
{
printf("Enter the working hour for the employee no. %d : ", i);
if (scanf("%d", &working_hour) != 1)
{
printf("\n\tPlease enter a number as woking hour.\n\n");
while (getchar() != '\n')
;
// above line discard the input characters untill getchar() reaches the new line character.
/* if I do not discard the input, after 'continue;' statement that input will be again taken
by scanf (In the line 17). It will be a infinite loop of error. */
continue;
}
// checking overtime
if (working_hour > 40)
{
pay = (working_hour - 40) * 120.00;
printf("\n\tOvertime working hours of Employee %d : %d", i, (working_hour - 40));
printf("\n\tPay of the overtime for Employee %d : Rs. %.2f\n\n", i, pay);
}
else
printf("\n\tEmployee %d did not work any overtime.\n\n", i);
i++; // changing to next employee
}
}/* Write a program to find the factorial value of any number entered
through the keyboard. */
/* Author - Amit Dutta, Date - 07th OCT, 2025 */
/* Let Us C, Chap - 5, Page - 84, Problem 5.2 */
#include <stdio.h>
int main()
{
int num, i = 1;
long long fact = 1;
printf("Enter the number : ");
// checking if the input is valid or not
if (scanf("%d", &num) != 1)
{
printf("\nPlease enter a number.");
return 1;
}
// result for the negetive input
if (num < 0)
{
printf("\nFactorial of %d : Undefined", num);
return 1;
}
// Hard codded result for input '0' (zero)
if (num == 0)
{
printf("\nFactorial of 0 : 1");
return 0;
}
// calculating result
while (i <= num) {
fact = fact * i;
i++;
}
printf("\nFactorial of %d : %d", num, fact);
return 0;
}/* Two numbers are entered through the keyboard. Write a program to
find the value of one number raised to the power of another */
/* Author - Amit Dutta, Date - 07th OCT, 2025 */
/* Let Us C, Chap - 5, Page - 84, Problem 5.3 */
#include <stdio.h>
int main()
{
double num, result;
int power, i = 1;
printf("Enter the numbers in 'num^power' format : ");
// checking if the input is valid or not
if (scanf("%lf^%d", &num, &power) != 2)
{
printf("\nPlease enter numbers.");
return 1;
}
// result for the negetive input
if (power < 0)
{
printf("\nPlease use a positive number as power.");
return 1;
}
// Hard codded result for input '0' (zero)
if (power == 0)
{
printf("\n%g to the power of %d is : 1", num, power);
return 0;
}
result = num;
while (i <= power - 1)
{
result = result * num;
i++;
}
printf("\n%g to the power of %d is : %g", num, power, result);
return 0;
}/* WAP to calculate area and perimeter of a rectangle
by accepting length and breadth as input. */
// Author - Amit Dutta, Date - 18th SEP, 2025
#include<stdio.h>
int main() {
double length, breadth, area, perimeter;
printf("Enter the length and breadth of the Rectangle : ");
scanf("%lf %lf", &length, &breadth);
area = length * breadth;
perimeter = 2 * (length + breadth);
printf("\nArea of the Rectangle : %g"
"\nPerimeter of the Rectangle : %g", area, perimeter);
return 0;
}
/* WAP to calculate area of a circle using math library
method. Take radius of the circle as input. */
/* Author - Amit Dutta, Date - 18th SEP, 2025 */
#include <stdio.h>
#include <math.h>
int main()
{
double r, area;
printf("Enter the radius of the circle : ");
scanf("%lf", &r);
area = M_PI * pow(r, 2);
printf("\nArea of the circle : %g", area);
return 0;
}/* WAP to accept diagonal of a square and calculate area, parimeter */
/* Author - Amit Dutta, Date - 18th SEP, 2025 */
#include <stdio.h>
#include <math.h>
int main()
{
double dia, side, area, peri;
printf("Enter the diagonal of the square : ");
scanf("%lf", &dia);
side = dia / sqrt(2);
area = pow(side, 2);
peri = 4 * side;
printf("\nArea of the square : %g"
"\nPerimeter of the square : %g",
area, peri);
return 0;
}/* WAP to calculate and display radius of a circle by taking the area as input. */
/* Author - Amit Dutta, Date - 18th SEP, 2025 */
#include <stdio.h>
#include <math.h>
int main()
{
double r, area;
printf("Enter the area of the circle : ");
scanf("%lf", &area);
r = sqrt(area / M_PI);
printf("\nRadius of the circle : %g", r);
return 0;
}/* WAP a program that accept number of days
as input and represent it as years, months and days. */
/* Author - Amit Dutta, Date - 19th SEP, 2025 */
#include <stdio.h>
int main()
{
int days, months, years, temp;
printf("Enter the No. of days : ");
scanf("%d", &days);
temp = days;
years = days / 365;
days = days % 365;
months = days / 30;
days = days % 30;
printf("%d Days = %d Years, %d Months, %d Days", temp, years, months, days);
return 0;
}/* WAP that accept seconds as input and represent it an hours, minutes and seconds. */
/* Author - Amit Dutta, Date - 19th SEP, 2025 */
#include <stdio.h>
int main()
{
int sec, hours, minutes, temp;
printf("Enter the no of seconds : ");
scanf("%d", &sec);
temp = sec;
hours = sec / 3600;
sec = sec % 3600;
minutes = sec / 60;
sec = sec % 60;
printf("\n%d Seconds = %d Hours, %d Minutes, %d Seconds.", temp, hours, minutes, sec);
return 0;
}/* WAP that accept basic salary of an employee and display gross salary,
net salary generated by below formula.
DA = 25% of the basic salary.
HRA = 12.5% of the basic salary.
PF = 10% of the basic salary.
gross salary = basic salary + da + hra
net salary = gross salary - pf
*/
/* Author - Amit Dutta, Date - 19th SEP, 2025 */
#include <stdio.h>
int main()
{
double bs, gs, ns, da, hra, pf;
printf("Enter the basic salary of the employee : ");
scanf("%lf", &bs);
da = bs * 0.25;
hra = bs * 0.125;
pf = bs * 0.10;
gs = bs + da + hra;
ns = gs - pf;
printf("\nGross Salary : %g"
"\nNet Salary : %g",
gs, ns);
return 0;
}/* WAP to multiply and divide a number by 4 without
using multiplication and division operator. */
/* Author - Amit Dutta, Date - 19th SEP, 2025 */
#include <stdio.h>
int main()
{
int num, multi, div;
printf("Enter the number : ");
scanf("%d", &num);
multi = num << 2;
div = num >> 2;
printf("Multiplication : %d"
"\nDivision : %d",
multi, div);
return 0;
}/* WAP to swap two integer variable without using Third variable. */
/* Author - Amit Dutta, Date - 19th SEP, 2025 */
#include <stdio.h>
int main()
{
int a = 4, b = 6;
printf("Before swap : A = %d and B = %d", a, b);
a = a ^ b;
b = a ^ b;
a = a ^ b;
printf("\nAfter swap : A = %d and B = %d", a, b);
return 0;
}/* WAP to calculate and display the valve of the given expression :
(1/a^3) + (1/(b+2)^3) + (1/(c^4 + root(2)))
take a, b, c as input.
*/
/* Author - Amit Dutta, Date - 19th SEP, 2025 */
#include <stdio.h>
#include <math.h>
int main()
{
double a, b, c, result;
printf("Enter the value for a, b and c : ");
scanf("%lf %lf %lf", &a, &b, &c);
result = (1 / pow(a, 3)) + (1 / pow((b + 2), 3)) + (1 / (pow(c, 4) + sqrt(2)));
printf("\nResult = %g", result);
return 0;
}#include<stdio.h>
int main() {
int a = 9, b = 4, c;
c = a + b;
printf("A + B = %d\n", c);
c = a / b;
printf("A / B = %d\n", c);
c = a % b;
printf("A %% B = %d\n", c);
return 0;
}
#include<stdio.h>
int main() {
int a = 5, b = 5, c = 10;
printf("a = b = %d\n", a == b);
printf("a > b = %d\n", a > b);
printf("a < b = %d\n", a < b);
return 0;
}
#include <stdio.h>
int main() {
int a = 5, b = 5, c = 10, result;
result = (a == b) && (c > b);
printf("Result is %d\n", result);
result = (a == b) && (c < b);
printf("Result is %d\n", result);
result = (a != b) || (c < b);
printf("Result is %d\n", result);
result = (a != b) || (c < b);
printf("Result is %d\n", result);
result = !(a != b);
printf("Result is %d\n", result);
result = !(a == b);
printf("Result is %d\n", result);
return 0;
}
// WAP to perform arithmatic operation on integer data
#include<stdio.h>
int main() {
int a, b, sum, sub, multi, div, mod;
printf("Enter 1st number : ");
scanf("%d", &a);
printf("Enter 2nd number : ");
scanf("%d", &b);
sum = a + b;
sub = a - b;
multi = a * b;
div = a / b;
mod = a % b;
printf("\nSum = %d", sum);
printf("\nSubtraction = %d", sub);
printf("\nMultiplication = %d", multi);
printf("\nDivision = %d", div);
printf("\nModulas = %d", div);
return 0;
}
/* WAP to swap two integers. Display both numbers
before and after swap */
#include<stdio.h>
int main() {
int a = 10, b = 20, temp;
printf("Before swap A : %d, B : %d", a, b);
temp = a;
a = b;
b = temp;
printf("\nAfter swap A : %d, B : %d", a, b);
return 0;
}
/* Bitwise AND '&' */
#include<stdio.h>
int main() {
unsigned int a = 4, b = 5, c = 6;
unsigned int x, y;
x = a & b;
y = b & c;
printf("x = %u y = %u", x, y);
return 0;
}
#include<stdio.h>
int main() {
int x = 25, y = 19, z;
z = x - y;
z = z & x ;
printf("Z = %d", z);
return 0;
}
/* Bitwise OR '|' */
#include<stdio.h>
int main() {
int x = 12, y = 14, z = 10, res;
x++;
z++;
x = x + y + z;
res = x | y;
z = res | z;
printf("x = %d y = %d z = %d res = %d", x, y, z, res);
return 0;
}
/* Bitwise NOT '~' */
#include<stdio.h>
int main() {
int x = 12, y = 15, z = 21;
int res, res1, res2;
res = x > 10;
res1 = ~res;
res2 = ~x;
printf("REs = %d, Res1 = %d, Res2 = %d", res, res1, res2);
return 0;
}
/* WAP to check a number is even or odd using bitwise operator */
#include<stdio.h>
int main() {
int x, res = 1;
printf("Enter a number : ");
scanf("%d", &x);
res = res & x;
if (res == 0) {
printf("\nInput %d is a even number.", x);
}
else {
printf("\nInput %d is a odd number.", x);
}
return 0;
}
/* WAP to calculate area of circle by accepting radius as input */
/* Author : Amit Dutta, Date : 15th September, 2025 */
#include<stdio.h>
#include<math.h>
int main() {
double r, area;
printf("Enter the radius of circle : ");
scanf("%lf", &r);
area = M_PI * r * r;
printf("\nArea : %lf", area);
return 0;
}
//sample code
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
printf("Hello world");
return 0;
}
//sample code with a new line charecter
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
printf("Hello\nworld");
return 0;
}
//WAP to perform addtion and multiplication of two integer numbers
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
int a, b, sum, multi;
printf("Enter the 1st number : ");
scanf("%d",&a);
printf("Enter the 2nd number : ");
scanf("%d",&b);
sum = a + b;
multi = a * b;
printf("\nSum = %d"
"\nMultiplication = %d",sum,multi);
return 0;
}
/* WAP to find and display the value of given expression :
((x+3)/4) - ((2x+4)/3) taking the value of x = 5 */
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
double x =5, result;
result = ((x + 3) / 4) - ((2 * x + 4) / 3);
printf("Result = %lf",result);
return 0;
}
/* A person is paid Rs. 455 for each day he works and fined
Rs. 150 for each day he remains absent. WAP to calculate his
monthly income taking the number of days present as input. */
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
int daily_wage = 455, fine = 150, present, absent, income;
printf("No of days present : ");
scanf("%d", &present);
absent = 30 - present;
income = (present * 455) - (absent * 150);
printf("\nIncome : %d",income);
return 0;
}
/* The normal temperature of human body
is 98.6 Degree Fahrenheit. WAP to convert the temperature
to Degree Celcius and display the output. */
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
double f = 98.6, c;
c = ((f - 32) * 5) / 9;
printf("Temperature in Celcius is : %lf",c);
return 0;
}
/* A shopkeeper offers 10% discount on printed
price of a digital camera. However a customer has
to pay 6% GST on the remaining amount. WAP to
calculate and display the amount to paid by the
customer, taking the printed price as input. */
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
double mrp, final_price, temp;
printf("Enter the printed price : ");
scanf("%lf", &mrp);
temp = mrp * 0.90;
final_price = temp * 1.06;
printf("\nCustomer have to pay : %lf", final_price);
return 0;
}
/* A shopkeeper offers 30% discount on purchasing an
item whereas the other shopkeeper offers 2 successive
discount of 20% and 10% for purchasing the same item.
WAP to caompute and display the discounted price of the
item by taking the price as input. */
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
double mrp, shop1, shop2, temp;
printf("Enter the price : ");
scanf("%lf", &mrp);
shop1 = mrp * 0.70;
temp = mrp * 0.80;
shop2 = temp * 0.90;
printf("\nShopkeeper 1 price : %lf"
"\nShopkeeper 2 price : %lf",shop1,shop2);
return 0;
}
/* WAP to calculate gross and net salary
by accepting basic salary as input.
IMP : DA = 30% of Basic Pay
HRA = 20% of Basic Pay
PF = 12.5% of Basic Pay
Gross Salary = Basic Pay + DA + HRA
Net Salary = Gross Salary - PF
*/
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
double bs, da, hra, pf, gs, ns;
printf("Enter the Basic Salary : ");
scanf("%lf", &bs);
da = bs * 0.3;
hra = bs * 0.2;
pf = bs * 0.125;
gs = bs + da + hra;
ns = gs - pf;
printf("\nGross Salary : %lf"
"\nNet Salary : %lf", gs, ns);
return 0;
}
/* WAP to find and display the difference
between compound Interest and Simple Interest.
Take principle amount as input.
Hint : si = (p * r * t) / 100
a = p * ((1 + (r / 100)) ^ t)
ci = a - p
*/
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
#include<math.h>
int main() {
double p, r, t, si, a, ci, dif;
printf("Enter the principle amount, rate of interest, time in year : ");
scanf("%lf %lf %lf", &p, &r, &t);
si = (p * r * t) / 100;
a = p * pow((1 + (r / 100)), t);
ci = a - p;
dif = ci - si;
printf("\nSimple Interest : %lf"
"\nCompound Interest : %lf"
"\nInterest Difference : %lf", si, ci, dif);
return 0;
}
/* The time period of a simple pendulam is
given by the formula :
t = 2 * pi * square_root(l / g)
WAP to calculate T take length(L) and gravity
as input
*/
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
#include<math.h>
int main() {
double l, g, t;
printf("Enter the Length and Gravity measures : ");
scanf("%lf %lf", &l, &g);
t = 2 * M_PI * sqrt(l / g);
// using M_PI variable for PI value from math.h header file
printf("\nTime Period : %lf", t);
return 0;
}
/* WAP to swap two integer variable without
using third variable */
// using Approch Mode : simple, slow, time consuming
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
int a = 4, b = 6;
printf("Before Swap : A = %d, B = %d", a, b);
a = a + b;
b = a - b;
a = a - b;
printf("\nAfter Swap : A = %d, B = %d", a, b);
return 0;
}
/* WAP to swap two integer variable without
using third variable */
// using Approch Mode : complex, fast, less time consumimg
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
#include<math.h>
int main() {
int a = 4, b = 6;
printf("Before Swap : A = %d, B = %d", a, b);
a = a ^ b;
b = a ^ b;
a = a ^ b;
printf("\nAfter Swap : A = %d, B = %d", a, b);
return 0;
}
/* WAP to accept the diagonal of
square. Find and display the area and
perimeter of the square. */
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
#include<math.h>
int main() {
double d, side, area, per;
printf("Enter the diagonal : ");
scanf("%lf", &d);
side = d / sqrt (2);
area = side * side;
per = 4 * side;
printf("\nArea of the Square : %lf"
"\nPerimeter of the Square : %lf", area, per);
return 0;
}
/*WAP to accept number of days and
display it after converting into
number of years, months and days */
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
int main() {
int day, month, year, temp;
printf("Enter the number of days : ");
scanf("%d", &day);
temp = day;
year = day / 365;
day = day % 365;
month = day / 30;
day = day % 30;
printf("\n%d Days = %d Years %d Months %d Days", temp, year, month, day);
return 0;
}
/* WAP to calculate and display radius of a
circle by taking the area as input */
// Author - Amit Dutta, Date - Unknown
#include<stdio.h>
#include<math.h>
int main() {
double area, r;
printf("Enter the area of a circle : ");
scanf("%lf", &area);
r = sqrt((7 * area) / 22);
printf("\nRadius : %lf", r);
return 0;
}
/* Find maximum between three number. */
// Author - Amit Dutta, Date - Unknown
#include <stdio.h>
int main()
{
int a, b, c, max;
printf("Enter the value for a, b, c : ");
scanf("%d %d %d", &a, &b, &c);
max = a;
if (max < b)
max = b;
if (max < c)
max = c;
printf("Maximum : %d", max);
return 0;
}/* WAP to input the cost price and selling price and
calculate profit, profit percentage, loss percentage or
display the manage nither profit nor loss. */
// Author - Amit Dutta, Date - Unknown
#include <stdio.h>
int main()
{
double cost, sell, pro, prop, loss, lossp;
printf("Enter the cost and selling price : ");
scanf("%lf %lf", &cost, &sell);
if (sell > cost)
{
pro = sell - cost;
prop = (pro / cost) * 100;
printf("Profit : RS %g, Profit Percentage : %g", pro, prop);
}
else if (sell < cost)
{
loss = cost - sell;
lossp = (loss / cost) * 100;
printf("Loss : RS %g, Loss Percentage : %g", loss, lossp);
}
else
printf("Neither loss nor Profit.");
return 0;
}/* WAP to input the distance covered and calculate
the amount to be paid by the passanger.
Distance Rate
=<5KM RS 90
next 10KM RS 20/KM
next 10KM RS 10/KM
more than 25KM RS 9/KM
*/
// Author - Amit Dutta, Date - Unknown
#include <stdio.h>
int main()
{
double dis, amt;
printf("Enter the distance : ");
scanf("%lf", &dis);
if (dis <= 5.0)
amt = 90.0;
else if (dis > 5.0 && dis <= 15.0)
amt = 90.0 + (dis - 5.0) * 20;
else if (dis > 15.0 && dis <= 25.0)
amt = 90.0 + 200.0 + (dis - 15.0) * 10;
else if (dis > 25.0)
amt = 90.0 + 200.0 + 100.0 + (dis - 25.0) * 9;
printf("\nAmount to be paid : %g", amt);
return 0;
}/* WAP to calculate and display the maturity amount
taking the sum and number of days as input.
No. of Days Rate of Interest
Upto 180 days 5.5 %
181 to 364 days 7.5 %
exact 365 days 9.0 %
more than 365 days 8.5 %
*/
// Author - Amit Dutta, Date - Unknown
#include <stdio.h>
int main()
{
double nod, amt, s, i;
printf("Enter the amount and the time in days : ");
scanf("%lf %lf", &s, &nod);
if (nod <= 180)
i = (s * 5.5 * (nod / 365)) / 100;
else if (nod > 180.0 && nod <= 364.0)
i = (s * 7.5 * (nod / 365)) / 100;
else if (nod == 365.0)
i = (s * 9.0 * 1) / 100;
else if (nod > 365.0)
i = (s * 8.5 * (nod / 365)) / 100;
amt = s + i;
printf("Amount to be paid : %g", amt);
return 0;
}/* WAP to input a positive number and check if it is a perfect
square number or not. */
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
// This code has not been compiled.
// If you find any issues, please create a new issue on GitHub regarding them.
#include <stdio.h>
#include <math.h>
int main()
{
int n, temp;
double sr;
printf("Enter the number : ");
scanf("%d", &n);
sr = sqrt(n);
temp = (int)sr;
if (temp * temp == n)
printf("\nThis is a perfect square.");
else
printf("\nThis is not a perfect square.");
return 0;
}/* WAP to find out smallest of three numbers without using if_else block. */
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
// This code has not been compiled.
// If you find any issues, please create a new issue on GitHub regarding them.
#include <stdio.h>
int main()
{
int a, b, c, min;
printf("Enter three number : ");
scanf("%d %d %d", &a, &b, &c);
min = (a < b && a < c) ? a : (b < a && b < c) ? b
: c;
printf("Minimum = %d", min);
return 0;
}/* WAP to input the total cost and compute the amount to be paid
by the customer. */
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
// This code has not been compiled.
// If you find any issues, please create a new issue on GitHub regarding them.
#include <stdio.h>
int main()
{
double cost, amt;
printf("Enter the total cost : ");
scanf("%lf", &cost);
if (cost <= 2000)
amt = cost * 0.94;
else if (cost > 2000 && cost <= 5000)
amt = cost * 0.9;
else if (cost > 5000 && cost <= 10000)
amt = cost * 0.85;
else if (cost > 10000)
amt = cost * 0.8;
printf("\nAmount to be paid : %g", amt);
return 0;
}/* WAP to check whether a year is leapyear or not. */
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
// This code has not been compiled.
// If you find any issues, please create a new issue on GitHub regarding them.
#include <stdio.h>
int main()
{
int year;
printf("Enter the year : ");
scanf("%d", &year);
if (year % 4 == 0 && year % 100 != 0)
printf("\nYear %d is a leapyear.", year);
else if (year % 400 == 0)
printf("\nYear %d is a leapyear (Century).", year);
else
printf("\nYear %d is not a leapyear.", year);
return 0;
}/* WAP to input the electricity unit consumed and calculate the total
bill amount according to the given condition :
for 1st 50 unit Rs. 0.50 per unit
next 100 unit Rs. 0.75 per unit
next 100 unit Rs. 1.20 per unit
above 250 unit Rs. 1.50 per unit
And additional charge of 20 percent is added to the bill.
*/
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
// This code has not been compiled.
// If you find any issues, please create a new issue on GitHub regarding them.
#include <stdio.h>
int main()
{
double unit, amt;
printf("Enter the electricity consp(unit) : ");
scanf("%lf", &amt);
if (unit <= 50)
amt = unit * 0.50;
else if (unit > 50 && unit <= 50)
amt = 25 + ((unit - 50) * 0.75);
else if (unit > 150 && unit <= 250)
amt = 25 + 75 + ((unit - 150) * 1.20);
else if (unit > 250)
amt = 25 + 75 + 120 + ((unit - 250) * 1.50);
amt = amt * 1.20;
printf("\nAmount to be paid : %g", amt);
return 0;
}/* WAP to input sum (p), rate of interest (r), time (t) and type of interest
('s' for simple interest amd 'c' for compound interest). Calculate and display
the interest earned
si = (p * r * t) / 100
compoundInterest = p * ((1 + r / 100)^t - 1)
*/
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
#include <stdio.h>
#include <math.h>
#include <ctype.h>
int main()
{
double principalAmount, rateOfInterest, timePeriod, simpleInterest, compoundInterest;
char mode;
printf("Enter the principle amount, Rate of interest, Time : ");
scanf("%lf %lf %lf", &principalAmount, &rateOfInterest, &timePeriod);
printf("\nEnter the mode ('s' : simple interest, 'c' : compound interest) : ");
scanf(" %c", &mode);
mode = tolower(mode);
switch (mode)
{
case 's':
simpleInterest = (principalAmount * rateOfInterest * timePeriod) / 100;
printf("\nSimple Interest : %g", simpleInterest);
break;
case 'c':
compoundInterest = principalAmount * (pow((1 + rateOfInterest / 100), timePeriod) - 1);
printf("\nCompound Interest : %g", compoundInterest);
break;
default:
printf("\nInvalid Input");
return 1;
}
return 0;
}/* Purchase Discount on Discount on
Amount Laptop Desktop
-------- ----------- -----------
Upto 20k 3.0% 5.0%
20001 - 50k 5.0% 7.5%
50001 - 75k 7.5% 10.5%
more than 75k 10.0% 15.0%
WAP to input amount of purchase and type of purchase ('L' : laptop, 'D' : desktop)
and display the discount amount and the discounted price (Net Amount).
*/
/* Author - Amit Dutta, Date - 8th OCT, 2025 */
// This code has not been compiled.
// If you find any issues, please create a new issue on GitHub regarding them.
#include <stdio.h>
#include <ctype.h>
int main()
{
double principal_amount, desktop_discount, laptop_discount, discount_amount, discounted_price;
char choice;
printf("Enter the purchase amount : ");
scanf("%lf", &principal_amount);
printf("Type of purchase ('L' : Laptop, 'D' : Desktop) : ");
scanf(" %c", &choice);
choice = toupper(choice);
if (principal_amount <= 20000)
{
laptop_discount = 0.03;
desktop_discount = 0.05;
}
else if (principal_amount > 20000 && principal_amount <= 50000)
{
laptop_discount = 0.05;
desktop_discount = 0.075;
}
else if (principal_amount > 50000 && principal_amount <= 75000)
{
laptop_discount = 0.075;
desktop_discount = 0.105;
}
else if (principal_amount > 75000)
{
laptop_discount = 0.1;
desktop_discount = 0.15;
}
switch (choice)
{
case 'L':
discount_amount = principal_amount * laptop_discount;
discounted_price = principal_amount - discount_amount;
printf("\nDiscount Amount : %g"
"\nDiscounted Price : %g",
discount_amount, discounted_price);
break;
case 'D':
discount_amount = principal_amount * desktop_discount;
discounted_price = principal_amount - discount_amount;
printf("\nDiscount Amount : %g"
"\nDiscounted Price : %g",
discount_amount, discounted_price);
break;
default:
printf("\nInvalid Input.");
return 1;
}
return 0;
}/* WAP to calculate factorial of a number */
/* Author - Amit Dutta, Date - 11th OCT, 2025 */
#include <stdio.h>
int main()
{
int i = 1, num, fact = 1;
printf("Enter the number : ");
if (scanf("%d", &num) != 1)
{
printf("\nPlease enter a number.");
return 1;
}
if (num == 0)
{
printf("\nFactorial of 0 : 1");
return 0;
}
if (num < 0)
{
printf("\nFactorial of %d : UNDEFINED", num);
return 0;
}
while (i <= num)
{
fact = fact * i;
i++;
}
printf("Factorial of %d : %d", num, fact);
return 0;
}/* WAP to perform addition of first n natural numbers. sum = 1 + 2 + 3 + ... */
/* Author - Amit Dutta, Date - 11th OCT, 2025 */
#include <stdio.h>
int main()
{
int num, i = 0, result = 0;
printf("Enter the value for n : ");
if (scanf("%d", &num) != 1)
{
printf("\nPlease enter a number.");
return 1;
}
if (num < 1)
{
printf("\nPlease enter a positive number.");
return 1;
}
while (i <= num)
{
result = result + i;
i++;
}
printf("\nResult : %d", result);
return 0;
}/* Display the first 15 terms of the series. */
/* Author - Amit Dutta, Date - 11th OCT, 2025 */
#include <stdio.h>
#include <math.h>
int main()
{
int i, r;
// 3, 6, 9, 12, ...
{
i = 3, r = 0;
printf("Series 1 (3, 6, 9, 12, ...) :");
while (i <= 15)
{
r = r + 3;
printf(" %d", r);
i++;
}
}
// 1, 4, 9, 16, ...
{
i = 1;
printf("\nSeries 2 (1, 4, 9, 16, ...) :");
while (i <= 15)
{
printf(" %d", i * i);
i++;
}
}
// 4, 8, 16, 32, ...
{
i = 1, r = 2;
printf("\nSeries 3 (4, 8, 16, 32, ...) :");
while (i <= 15)
{
r = r * 2;
printf(" %d", r);
i++;
}
}
// 0, 7, 26, ...
{
i = 1, r;
printf("\nSeries 4 (0, 7, 26, ...) :");
while (i <= 15)
{
r = (int)pow(i, 3) - 1;
printf(" %d", r);
i++;
}
}
return 0;
}
/* Find the sum of the series */
/* Author - Amit Dutta, Date - 11th OCT, 2025 */
#include <stdio.h>
#include <math.h>
int main()
{
double a, res, n;
int i;
// s = (a ^ 2) + (a ^ 2 / 2) + (a ^ 2 / 3) + ... + (a ^ 2 / 10)
{
res = 0, i = 1;
printf("--- s = (a ^ 2) + (a ^ 2 / 2) + (a ^ 2 / 3) + ... + (a ^ 2 / 10) ---");
printf("\nEnter the number : ");
scanf("%lf", &a);
while (i <= 10)
{
res = res + ((a * a) / i);
i++;
}
printf("S = %g", res);
}
// s = 1 + (2 ^ 2 / a) + (3 ^ 3 / a ^ 2) + ... + n
{
res = 0, i = 0;
printf("\n--- // s = 1 + (2 ^ 2 / a) + (3 ^ 3 / a ^ 2) + ... + n ---");
printf("\nEnter the value for a and n : ");
scanf(" %lf %lf", &a, &n);
while (i <= n - 1)
{
res = res + (pow(i + 1, i + 1) / pow(a, i));
i++;
}
printf("S = %g", res);
}
return 0;
}/* WAP to input a number and check whether it is a Niven number
or not. (When a number is divisible by its sum of digit) e.g. : n = 126*/
/* Author - Amit Dutta, Date - 11th OCT, 2025 */
#include <stdio.h>
int main()
{
int n, temp, sod = 0;
printf("Enter the number : ");
scanf("%d", &n);
temp = n;
while (temp > 0)
{
sod = sod + (temp % 10);
temp = temp / 10;
}
if (n % sod == 0)
printf("\nIt is Niven number.");
else
printf("\nIt is not a Niven number.");
return 0;
}