为什么？？？

代码：

#include <bits/stdc++.h>
using namespace std;
long long ans;

int main() {
	long long n;
	cin >> n;
	for (long long i = 1; i <= n; i++) {
		for (long long k = 1; k <= n; k++) {
			for (long long j = 1; j <= n; j++) {
				if (i * i + k * k == j * j && j <= n) {
					ans++;
				}
			}
		}
	}
	cout << ans;
	return 0;
}