题解 | #合并表记录#

#include <iostream>
#include <map>

using namespace std;

int main()
{
    int n;
    cin >> n;
    map<int, int> mymap;
    while (n--)
    {
        int a, b;
        cin >> a >> b;
        mymap[a] += b;
    }
    for (auto it : mymap)
    {
        cout << it.first << " " << it.second << endl;
    }
}

map 默认按照key升序排列