ZOJ 3609 Modular Inverse(暴力)

#include<iostream>
#include<cstdio>
#include<set>
#include<string>
#include<string.h>
#include<cstring>
#include<vector>
#include<map>
#include<queue>
#include<stack>
#include<cctype>
#include<algorithm>
#include<sstream>
#include<utility>
#include<cmath>
#include<functional>
#define mt(a) memset(a,0,sizeof (a))
#define fl(a,b,c) fill(a,b,c)
#define SWAP(a,b,t) (t=a,a=b,b=t)

#define inf 1000000000+7

using namespace std;
typedef long long ll;

int main()
{
int T;
cin >> T;
while (T--)
{
ll a, x;
cin >> a >> x;
ll flag = 0,cot=0;
for (ll i = 0; i <= 5000; i++)
{
if ((x*i+1)%a==0)
{
flag = 1; cot = (x*i+1)/a; break;
}
}
if (flag)printf("%lld\n", cot);
else printf("Not Exist\n");
}
return 0;
}