prime check in c
#include <stdio.h>
int main() {
int num, i, flag = 0;
printf("Enter a number: ");
scanf("%d", &num);
for (i = 2; i <= num / 2; ++i) {
if (num % i == 0) {
flag = 1;
break;
}
}
if (num == 1) {
printf("1 is neither prime nor composite.");
} else {
if (flag == 0)
printf("%d is a prime number.", num);
else
printf("%d is not a prime number.", num);
}
return 0;
}