HDU 2092 整数解 --- 水题

x+y = n, x*y = m;

y = n - x;

x * ( n - x) = m

nx - x^2 = m;

x^2 - nx + m = 0;

△ = sqrt(n^2 - 4m)

要有整数解即△需要为可开方数即可。

/* HDU 2092 整数解 --- 水题 */
#include <cstdio>
#include <cmath>

int main()
{
    double n, m;
    while (scanf("%lf%lf", &n, &m) == 2 && (n+m)){
        n = n*n - 4 * m;
        m = (int)sqrt(n);
        if (m*m == n){
            printf("Yes\n");
        }
        else{
            printf("No\n");
        }
    }

    return 0;
}