C Program to Calculate the Sum of Natural Numbers

Source code:

#include <stdio.h>
int main()
{
    int n, i, sum = 0;
    
    printf("Enter a positive integer: ");
    scanf("%d",&n);

    for(i=1; i <= n; ++i)
    {
        sum += i;   // sum = sum+i;
    }

    printf("Sum = %d",sum);

    return 0;
}

Output:

Enter a positive integer: 100
Sum = 5050

Read More

C Program to Display Factors of a Number

Source code:

#include <stdio.h>
int main()
{
    int number, i;

    printf("Enter a positive integer: ");
    scanf("%d",&number);

    printf("Factors of %d are: ", number);
    for(i=1; i <= number; ++i)
    {
        if (number%i == 0)
        {
            printf("%d ",i);
        }
    }

    return 0;
}

Output:

Enter a positive integer: 60
Factors of 60 are: 1 2 3 4 5 6 12 15 20 30 60

Read More

C Program to Check Whether a Number is Prime or Not

Source code:

#include <stdio.h>
int main()
{
    int n, i, flag = 0;

    printf("Enter a positive integer: ");
    scanf("%d",&n);

    for(i=2; i<=n/2; ++i)
    {
        // condition for nonprime number
        if(n%i==0)
        {
            flag=1;
            break;
        }
    }

    if (flag==0)
        printf("%d is a prime number.",n);
    else
        printf("%d is not a prime number.",n);
    
    return 0;
}

Output:

Enter a positive integer: 29
29 is a prime number.

Read More

C Program to Check Leap Year

Source code:

#include <stdio.h>

int main()
{
    int year;

    printf("Enter a year: ");
    scanf("%d",&year);

    if(year%4 == 0)
    {
        if( year%100 == 0)
        {
            // year is divisible by 400, hence the year is a leap year
            if ( year%400 == 0)
                printf("%d is a leap year.", year);
            else
                printf("%d is not a leap year.", year);
        }
        else
            printf("%d is a leap year.", year );
    }
    else
        printf("%d is not a leap year.", year);
    
    return 0;
}

Output 1:

Enter a year: 1900
1900 is not a leap year.

Output 2:

Enter a year: 2012
2012 is a leap year.

Read More

C Program to Calculate Area and Circumference of circle

Source Code:

#include<stdio.h>

int main() {

   int rad;
   float PI = 3.14, area, ci;

   printf("\nEnter radius of circle: ");
   scanf("%d", &rad);

   area = PI * rad * rad;
   printf("\nArea of circle : %f ", area);

   ci = 2 * PI * rad;
   printf("\nCircumference : %f ", ci);

   return (0);
}

Output:

Enter radius of a circle : 1

Area of circle : 3.14

Circumference  : 6.28

Read More