ham so nguyen to

// viet ham ktra so nguyen to

#include<stdio.h>

#include<conio.h>

#include<math.h>

int ktra_so_ngto(int i, int j,int dem);

int ktra_so_ngto(int i, int j,int dem)

{

dem = 0;

for (j=1;j<=i;j++){

if (i%j==0)

dem++;

}

return dem;

}

int main()

{

int n,i,j,dem;

do

{

printf("Nhap n = "); scanf("%d",&n);

}

while (n<1 || n>999);

printf("Cac so nguyen to tu 1 den %d la:",n); for (i=1;i<=n;i++){

dem = ktra_so_ngto(i,j,dem);

if (dem==2)

printf(" %d",i);

}

return 0; }