Question

write a.program and check whether it is a prime number or not​

Answer 1

Answer:

#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 non-prime

       if (n % i == 0) {

           flag = 1;

           break;

       }

   }

   if (n == 1) {

       printf("1 is neither prime nor composite.");

   }

   else {

       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.

Explanation:

Answer 2

Explanation:

Program to Check Prime Number

Enter a positive integer: 29 29 is a prime number. In the program, a for loop is iterated from i = 2 to i < n/2 . If n is perfectly divisible by i , n is not a prime number. In this case, flag is set to 1, and the loop is terminated using the break statement.