java语言实现

import java.util.Scanner;
import java.util.Set;
import java.util.TreeMap;

public class Main {
public static void main(String[] args) {

    Scanner scanner = new Scanner(System.in);

    if (scanner.hasNext()) {

        Integer integer = Integer.valueOf(scanner.nextLine());
        TreeMap<Integer,Integer> treeMap = new TreeMap<>();
        for (int i = 0; i < integer; i++) {
            String[] strings = scanner.nextLine().split(" ");
            Integer remove = 0;
            if (treeMap.containsKey(Integer.valueOf(strings[0]))) {
                remove = treeMap.remove(Integer.valueOf(strings[0]));
            }

            treeMap.put(Integer.valueOf(strings[0]) ,Integer.valueOf(strings[1])+ remove);

        }
        Set<Integer> integers = treeMap.keySet();
        for (Integer integerTemp : integers) {
            System.out.println(integerTemp+ " " + treeMap.get(integerTemp));
        }

    }

}

}