Thuật toán tìm SNT c++

#include <iostream>
#include <conio.h>
#include <cmath>

using namespace std;
int main()
{
    int n,i;
    cout<<"nhap n=";
    cin>>n;
 int laSNT=1;
    for (i=0;i<=sqrt(n) && laSNT;i++)
        laSNT=n%i;
    if (laSNT)
        cout<<n<<" la so nguyen to";
   getch();
}