题解 | 【模板】分数取模

#include <iostream>

using namespace std;

typedef long long LL;

const int P = 1e9 + 7;

LL qpow(int b,int c){
    if(c == 0) return 1;
    LL res = 1 % P;
    while(c){
        if(c & 1){
            res = res * b % P;
        }
        b = (long long)b * b % P;
        c = c >> 1;
    } 
    return res;
}
int main() {

    int t;
    cin>>t;
    while(t--){
        int a,b;
        cin>>a>>b;
        a = (a % P + P) % P;
        long long res = a * qpow(b,P - 2) % P; 
        cout<<res<<"\n";
    }
}
// 64 位输出请用 printf("%lld")