ACGO欢乐赛#42题解

Solution

暴力枚举从 $\min(a,b)$ 到 $2$ 的所有数看是否有为 $\gcd(a,b)$ 的因数的就输出，否则无解。

Code

#include <bits/stdc++.h>
#include <cstdio>
#define int long long
#define ull unsigned long long
#define mod 998244353
#define MOD 1000000007
using namespace std;
const int N = 2e6 + 5,maxn = 3e3 + 5;
const double goldnum = (sqrt (5) + 1) / 2;
inline int read ()
{
	int x = 0;
	bool f = 1;
	char c = getchar ();
	while (c < '0' || c > '9') f = (c == '-' ? !f : f),c = getchar ();
	while (c >= '0' && c <= '9') x = (x << 1) + (x << 3) + (c ^ 48),c = getchar ();
	return (f ? x : -x);
}
inline void write (int x)
{
	if (x < 0) putchar ('-'),x = -x;
	if (x > 9) write (x / 10);
	putchar (x % 10 + '0');
	return ;
}
signed main ()
{
	int T;
	cin >> T;
	while (T --)
	{
		int a,b;
		cin >> a >> b;
		int f = 0;
		for (int i = min (a,b);i >= 1;i --)
		{
			if (a % i == 0 && b % i == 0) f ++;
			if (f == 2)
			{
				cout << i << endl;
				break;
			}
		}
		if (f == 1) cout << -1 << endl;
	}
	return 0;
}