题解 | #合并表记录#

#include <iostream>
#include <hash_map>
#include<bits/stdc++.h>

using namespace std;

int main() {
    int n;
    cin >> n ;
    
    pair<int, int> input;
    map<int, int> mapValue;
    
    while (n--) {
        cin >> input.first >> input.second;
        if (mapValue.find(input.first) != mapValue.end()){
            mapValue[input.first] += input.second;
        }
        else{
            mapValue[input.first] = input.second;
        }
    }

    for (auto it = mapValue.begin(); it != mapValue.end(); it++){
        cout << it->first <<" "<< it->second << endl;
    }
    return 0;
}