prime number in c
#include <stdio.h>
int isPrime(int num);
int main() {
int n;
printf("Enter a positive integer: ");
scanf("%d", &n);
if (isPrime(n))
printf("%d is a prime number.\n", n);
else
printf("%d is not a prime number.\n", n);
return 0;
}
int isPrime(int num) {
if (num <= 1)
return 0;
for (int i = 2; i * i <= num; i++) {
if (num % i == 0)
return 0;
}
return 1;
}