C++ 代码

#include<bits/stdc++.h>
using namespace std;
map<int,double,greater<int>> mp;
int main(){
    int n,m;
    cin>>n;
    for(int i =0;i<n;i++) {
        int a;
        double d;
        cin>>a>>d;
        mp[a]=d;
    }
    cin>>m;
    for(int i = 0;i<m;i++){
        int aa;
        double dd;
        cin>>aa>>dd;
        mp[aa] +=dd; 
    }
    int num=0;
    for(auto item:mp){
        if(item.second!=0) num++;
    }
    cout<<num<<" ";
    for(auto item:mp){
        if(item.second!=0) printf("%d %.1lf ",item.first,item.second);
    }
    return 0;
}