poj 2126 Factoring a Polynomial

#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>using namespace std;int main(){    int n;    scanf("%d", &n);    if (n <= 1)    {        printf("YESn");        return 0;    }    if (n > 2)    {        printf("NOn");        return 0;    }    int a, b, c;    scanf("%d%d%d", &a, &b, &c);    if (b * b - 4 * a * c >= 0)        printf("NOn");    else        printf("YESn");    return 0;}