题解 | #合并表记录#

1、使用treeMap顺序输出 2、每次put的时候，校验是否存在该key,存在就取出来叠加当前value

/*
 * Copyright (c) Huawei Technologies Co., Ltd. 2022-2022. All rights reserved.
 */
import java.util.TreeMap;
import java.util.Map;
import java.util.Scanner;

/**
 * 4
 * 0 1
 * 0 2
 * 1 2
 * 3 4
 *
 * 输出：
 * 0 3
 * 1 2
 * 3 4
 *
 * @since [2022-04-01]
 */
public class Main {

    public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
        while (sc.hasNext()){
            int next = sc.nextInt();
            TreeMap<Integer,Integer> tableMap = new TreeMap<>();
            for (int i = 0; i < next; i++) {
                int key = sc.nextInt();
                int value = sc.nextInt();
                if (tableMap.containsKey(key)){
                    tableMap.put(key,tableMap.get(key)+value);
                }else {
                    tableMap.put(key,value);
                }
            }
            for (Integer key: tableMap.keySet()) {
                System.out.println(key+" "+tableMap.get(key));
            }
        }
    }
}