C Program Prime Number Code Example

Example 1: c program to check prime number using for loop

#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; }

Example 2: prime number c

#include <stdio.h> int main() {    int i, num, p = 0;    printf("Please enter a number: \n");    scanf("%d", &num);    for(i=1; i<=num; i++)    {       if(num%i==0)       {          p++;       }    }    if(p==2)    {       printf("Entered number is %d "\              "and it is a prime number.",num);    }    else    {       printf("Entered number is %d "\              "and it is not a prime number.",num);    } }