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Problem Statement

Write a C program with a user-defined function to check whether a given number is prime or not.

Solution

#include <stdio.h>

int isPrime(int n) {
    if (n < 2) return 0;
    for (int i = 2; i * i <= n; i++)
        if (n % i == 0) return 0;
    return 1;
}

int main() {
    int n;
    scanf("%d", &n);
    printf(isPrime(n) ? "Prime\n" : "Not Prime\n");
    return 0;
}

Input

17

Output

Prime