题解 | #合并表记录#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner fzhinput = new Scanner(System.in);
        int num = fzhinput.nextInt();
        int result[][]= new int[num][2];
        int i,j;
        for(i=0;i<num;i++){
            result[i][0]= fzhinput.nextInt();
            result[i][1] = fzhinput.nextInt();
        }
        for(i=0;i<num;i++){
            for(j=num-1;j>i;j--){
                if(result[i][0]==result[j][0]){
                    result[i][1]= result[i][1]+result[j][1];
                    result[j][0]=-1;
                }
            }
            
        }

        int[][] filteredResult = Arrays.stream(result)
                .filter(arr -> arr[0] != -1)
                .toArray(int[][]::new);

        Arrays.sort(filteredResult, Comparator.comparingInt(arr -> arr[0]));

        for(i=0;i<filteredResult.length;i++){
            System.out.println(filteredResult[i][0]+" "+filteredResult[i][1]);
        }
        
        
    }
}