(PCC)::[How-to-write-a-C-Program-to-Check-Whether-a-Number-is-Prime-or-Not]::[c]
//Program to Check Prime Number #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; }