一遍AC 嘿嘿

#include <iostream>

int main()
{
    using namespace std;
    int N;
    cin >> N; // 输入键值对的个数
    int sum[1000] = {0};
    int index, value;

    for(int i = 0; i < N; ++i) {
        cin >> index >> value;
        sum[index] = sum[index] + value;
    }
    for(int i = 0; i < 1000; ++i) {
        if(sum[i] != 0) {
            cout << i << " " << sum[i] << endl;
        }
    }
    return 0;
}