欧几里得算法-最大公约数

#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long LL;

LL gcd(LL a, LL b) {
    return !b ? a : gcd(b, a % b);
}

int main() {
    int n;
    cin >> n;
    while (n--) {
        LL a, b;
        cin >> a >> b;
        cout << gcd(a, b) << endl;
    }
    return 0;
}