题解 | #合并表记录#

#include <iostream>
#include "map"
using namespace std;

int main() {
    map<int, int> mapNUm;
    int i;
    cin >> i;
    while (i-- != 0) {
        int a;
        int b;
        cin >> a >> b;
        auto it = mapNUm.find(a);
        if (it != mapNUm.end()) {
            mapNUm[a] = mapNUm[a] + b;
        }
        else {
            mapNUm[a] = b;
        }
    
    }

    for (auto i : mapNUm) {
        cout << i.first << " " << i.second << endl;
    }
}
// 64 位输出请用 printf("%lld")