题解 | #合并表记录#

TreeMap自动排序

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        Map<Integer,Integer> map = new TreeMap();
        for(int i = 0; i<n; i++){
            Integer key = in.nextInt();
            Integer value = in.nextInt();
            if(map.containsKey(key)){
                map.put(key,value+map.get(key));
            }else{
                map.put(key,value);
            }
        }
        Set<Map.Entry<Integer, Integer>> entries = map.entrySet();
        for(Map.Entry<Integer, Integer> e:entries){
            System.out.println(e.getKey()+" "+e.getValue());
        }
    }
}