/* Bai tap 1_16 - Tinh xem so N co phai la so nguyen to khong? */

#include <stdio.h>

#include <math.h>

void main()

{

int N, i, OK = 1;

printf("

Nhap gia tri N : ");

scanf("%d", &N);

for (i=2; i<(int)sqrt(N); i++)

if (N%i == 0)

{

OK = 0;

break;

}

if (OK)

printf("

So %d la so nguyen to.", N);

else

printf("

So %d khong phai la so nguyen to.", N);

getch();

}