题解 | #合并表记录#

使用map记录val，利用vector记录索引并去重，排序后依次输出

#include <algorithm>
#include <iostream>
#include <map>
#include <vector>
using namespace std;

int main() {
    int num = 0;
    cin >> num;

    std::map<int, int> count;
    std::vector<int> store_ind;

    for(int i = 0; i < num; i ++){
        int ind, val = 0;
        cin >> ind >> val;

        if(count.find(ind) == count.end()){
            count[ind] = val;
            store_ind.push_back(ind);
        }
        else
            count[ind] += val;
    }
    sort(store_ind.begin(), store_ind.end());
    for(int i = 0; i < size(store_ind); i ++){
        cout << store_ind[i] << " " << count[store_ind[i]] << endl;
    }

}
// 64 位输出请用 printf("%lld")