UVa 11889 Benefit

枚举c的约数b ，判断a*b/gcd(a,b)是否等于c。b不能整除c就是无解。注意会爆int

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
#include <vector>
#include <algorithm>
#define LL long long
LL gcd(LL a,LL b){
	if(b==0) return a;
	return gcd(b,a%b);
}

vector <LL> Div;
int main(){
	int T;
	scanf("%d",&T);
	while(T--){
		LL a,b;
		scanf("%lld%lld",&a,&b);
		if(b%a!=0) printf("NO SOLUTION\n");
		Div.clear();
		for(LL i=1;i*i<=b;i++){
			if(b%i==0){
				Div.push_back(i);
				if(i!=b/i) Div.push_back(b/i);
			}
		}
		sort(Div.begin(),Div.end());
		for(int i=0;i<Div.size();i++){
			LL t=Div[i];
			if(a*t/gcd(a,t)==b){
				printf("%lld\n",t);
				break;
			}
		}
	}
	return 0;
}