错误原因（看不懂）

Wrong Answer.wrong answer 1st numbers differ - expected: '98580.2390390691', found: '33587.6307142972', error = '0.6592863738'

记录

code

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

const double ESP = 1e-9;

int main()
{
	cin.tie(0)->sync_with_stdio(0);
	cout.precision(15);
	int T, n, m;
	cin >> T;
	while (T--)
	{
		cin >> n >> m;
		if (__gcd(n, m) == 1)
		{
			cout << sqrt(n * n + m * m) << '\n';
		}
		else
		{
			double ans = 1e9, k = 1.0 * m / n;
			for (int x = 1; x < n; x++)
			{
				int y = k * x - 1;
				if (__gcd(n - x, m - y) == 1 && __gcd(x, y) == 1 && fabs(y - k * x) > ESP)
				{
					ans = min(ans, sqrt(x * x + y * y) + sqrt((n - x) * (n - x) + (m - y) * (m - y)));
				}
				y++;
				if (__gcd(n - x, m - y) == 1 && __gcd(x, y) == 1 && fabs(y - k * x) > ESP)
				{
					ans = min(ans, sqrt(x * x + y * y) + sqrt((n - x) * (n - x) + (m - y) * (m - y)));
				}
				y++;
				if (__gcd(n - x, m - y) == 1 && __gcd(x, y) == 1 && fabs(y - k * x) > ESP)
				{
					ans = min(ans, sqrt(x * x + y * y) + sqrt((n - x) * (n - x) + (m - y) * (m - y)));
				}
			}
			cout << ans << '\n';
		}
	}
}