国王游戏

 

#include <bits/stdc++.h>
using namespace std;
const int N = 1010;
int n;
typedef pair<int, int> PII;
PII ps[N]; //peoples
vector<int> mul(vector<int> a, int b) { //大整数a乘以一个小整数b
    vector<int> c;
    int t = 0;
    for (int i = 0; i < a.size(); i++) {
        t += a[i] * b;
        c.push_back(t % 10);
        t /= 10;
    }
    while (t) {
        c.push_back(t % 10);
        t /= 10;
    }
    return c;
}
vector<int> div(vector<int> a, int b) { //大整数a除以一个小整数b
    vector<int> c;
    bool is_first = false; //为了避免商有很多个0
    //表示前面是否已经有非零位了
    int t = 0;
    for (int i = a.size() - 1; i >= 0; i--) {
        t = t * 10 + a[i];
        int x = t / b;
        if (x || is_first) {
            is_first = true;
            c.push_back(x);
        }
        t %= b;
    }
    reverse(c.begin(), c.end());
    return c;
}
vector<int> max_vec(vector<int> a, vector<int> b) { //vector的max函数
    if (a.size() > b.size()) {
        return a;
    }
    if (a.size() < b.size()) {
        return b;
    }
    for (int i = a.size() - 1; i >= 0; i--) {
        if (a[i] > b[i]) {
            return a;
        } else if (a[i] < b[i]) {
            return b;
        }
    }
    return a;
}
void output(vector<int> a) {
    for (int i = a.size() - 1; i >= 0; i--) {
        cout << a[i];
    }
    cout << endl;
}
int main() {
    cin >> n;
    for (int i = 0; i <= n; i++) { //存储所有人信息
        int a, b;
        cin >> a >> b;
        ps[i] = {a * b, a};
    }
    sort(ps + 1, ps + 1 + n);
    vector<int> A; //存储那个大整数
    A.push_back(1);
    vector<int> res; //存储答案
    res.push_back(0);
    for (int i = 0; i <= n; i++) { //开始遍历
        if (i) { //国王不会给自己发奖励，从1开始才会更新答案
            res = max_vec(res, div(A, ps[i].first / ps[i].second));
        }
        A = mul(A, ps[i].second);
    }
    output(res);
    return 0;
}