c program for prime code example

Example 1: prime numbers in c

#include<stdio.h>
main() {
    int n, i, count=0;
    printf("Enter Number");
    scanf("%d",&n);
   
    for ( i = 1; i<= n; i++) {
        if (n % i == 1) {
            count++;
        }
    }
    if( count == 2) {
        printf("Prime Number");
    }
    else {
        printf("Not A  Prime Number");
    }
}

Example 2: 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;
}