题目链接：csoj | J. Rikka with Square Numbers (scnu.edu.cn)

题目解析：

代码如下：

#include<iostream>
#include<math.h>
#include<algorithm>
using namespace std;

int main()
{
	ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

	int T;
	cin >> T;
	
	while(T--)
	{
		int a, b;
		cin >> a >> b;
		if (a < b) swap(a, b);
		int d = a - b;
		int tm = (int)sqrt(d);
		if (tm * tm == d)
		{
			cout << "1" << endl;
			continue;
		} 
		
		if (d % 2 != 0 || d % 4 == 0) cout << "2" << endl;
		else
		{
			bool flag = false;
			for (int i = 1; i <= d / i; i++)
			{
				int t = d - (i * i);
				tm = (int)sqrt(t);
				if (tm * tm == t)
				{
					flag = true;
					break;
				}
			}
			if (flag) cout << "2" << endl;
			else cout << "3" << endl;
		}
	}
	
	return 0;
}