代码（对着题解改了好久）：

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define qwq ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)

signed main()
{
	qwq;
	int k;
	cin >> k;
	while (k --)
	{
		int n, e, d, b, c, delta;
		cin >> n >> e >> d;
		b = (-n - e * d + 2), c = n;
		delta = b * b - 4 * c;//▲= b^2 + 4c
		if (delta < 0)
			cout << "NO" << endl;
		else if (sqrt(delta) * sqrt(delta) != delta)
			cout << "NO" << endl;
		else if (-b + sqrt(delta) / 2 < 0)
			cout << "NO" << endl;
		else
			cout << min(-b + sqrt(delta) / 2, n / (-b + sqrt(delta) / 2)) << " " << max(-b + sqrt(delta) / 2, n / (-b + sqrt(delta) / 2)) << endl;	
	}
	return 0;
}