GCD LCM UVA

两个数的最小公倍数和最大公约数肯定是倍数关系

然后又让求使得a最小  因为 a = m * gcd

令m = 1 时 a取得最小  即gcd

则b = lcm

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
#include <vector>
#include <cmath>
#define mem(a, b) memset(a, b, sizeof(a))
using namespace std;
const int maxn = 10010, INF = 0x7fffffff;
int main()
{
    int T;
    int n, m;
    cin>> T;
    while(T--)
    {
        cin>> n >> m;
        if(m % n == 0)
            cout<< n << " " << m <<endl;
        else
            cout<< -1 <<endl;
    }
    return 0;
}