题解 | #合并表记录#

import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        TreeMap<Integer,Long> treeMap = new TreeMap<>();
        String n = sc.nextLine();
        while(sc.hasNext()){
            String str = sc.nextLine();
            String[] arr = str.split(" ");
            Long old_v = treeMap.get(Integer.parseInt(arr[0]));
            Long new_v = Long.parseLong(arr[1]);
            if(old_v != null){
                 new_v += old_v;
            }
            treeMap.put(Integer.parseInt(arr[0]),new_v);
        }
        
        treeMap.keySet().forEach(key ->{
            System.out.println(key+" "+treeMap.get(key));
        });
        
    }
}