#include<bits/stdc++.h>
typedef long long ll;

using namespace std;
const int N=1010;
struct Node{
    int l,r;
}node[N];

bool cmp(Node a,Node b){
    return a.l*a.r<b.l*b.r;
}

vector<int> mul(vector<int>a,int b){//高精度乘法
    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){//高精度除法
    vector<int> c;
    bool flag=true;
    int t=0;
    for(int i=a.size()-1;i>=0;i--){
        t=t*10+a[i];
        int x=t/b;
        if(!flag||x){
            flag=false;
            c.push_back(x);
        }
        t%=b;
    }
    reverse(c.begin(),c.end());
    return c;
}


vector<int>max_vec(vector<int>a,vector<int>b){
    if(a.size()>b.size()) return a;
    if(a.size()<b.size()) return b;//从最高位比较
    if(vector<int>(a.rbegin(),a.rend())>vector<int>(b.rbegin(),b.rend()))
        return a;
    else
        return b;
}

int main(void){
    int n;
    cin>>n;
    for(int i=0;i<=n;i++)
        cin>>node[i].l>>node[i].r;
    sort(node+1,node+n+1,cmp);
    vector<int>a(1,1);
    vector<int>res(1,0);
    for(int i=0;i<=n;i++){
        if(i) res=max_vec(res,div(a,node[i].r));
        a=mul(a,node[i].l);
    }
    for(int i=res.size()-1;i>=0;i--)
        cout<<res[i];
    cout<<endl;
    return 0;
}

高精度写法

过一半

#include <bits/stdc++.h>

using namespace std;

struct Minister{
  int a,b;
  bool operator<(const Minister& other)const{
    return a*b < other.a*other.b;
  }
};

int main()
{
  int n;
  cin>>n;
  vector<Minister>ministers(n+1);
  for(int i = 0;i<=n;++i)
  {
    cin>>ministers[i].a>>ministers[i].b;
  }
  sort(ministers.begin()+1,ministers.end());
  long long product = ministers[0].a;
  long long  max_coins = 0;
  for(int i = 1;i<=n;i++)
  {
    max_coins = max(max_coins,product/ministers[i].b);
    product *= ministers[i].a;
  }
  cout << max_coins<<endl;

  return 0;
}