题解 | #合并表记录#

import java.util.Scanner;
import java.util.ArrayList;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextLine()) { // 注意 while 处理多个 case

            int length = Integer.valueOf(in.nextLine());

            ArrayList<Integer> arrlIndex = new ArrayList<Integer>();
            ArrayList<Integer> arrlValue = new ArrayList<Integer>();

            // System.out.println(length);

            for (int i = 0; i < length; i++) {
                String twoNum = in.nextLine();
                int index = Integer.valueOf(twoNum.split(" ")[0]);
                int value = Integer.valueOf(twoNum.split(" ")[1]);

                if (arrlIndex.size() == 0) {
                    arrlIndex.add(index);
                    arrlValue.add(value);
                    //System.out.println('a');

                } else {
                    for (int j = 0; j < arrlIndex.size(); j++) {
                        if (index == arrlIndex.get(j)) {
                            arrlValue.set(j, arrlValue.get(j) + value);
                            //System.out.println('b');
                            break;
                        } else if (j == arrlIndex.size() - 1) {
                            arrlIndex.add(index);
                            arrlValue.add(value);
                            break;
                        } else {
                            continue;
                        }
                    }
                }
            }

            int length2 = arrlIndex.size();
            //System.out.println(length2);

            for (int i = 0; i < length2 - 1; i++) {
                for(int j =0;j<length2-1;j++){
                    int tempNum = 0;
                    int tempNum2 = 0;
                    if (arrlIndex.get(j) > arrlIndex.get(j + 1)) {
                        tempNum = arrlIndex.get(j);
                        arrlIndex.set(j, arrlIndex.get(j + 1));
                        arrlIndex.set(j + 1, tempNum);

                        tempNum2 = arrlValue.get(j);
                        arrlValue.set(j, arrlValue.get(j + 1));
                        arrlValue.set(j + 1, tempNum2);
                    } else {
                        continue;
                    }
                }
            }
            for (int i = 0; i < length2; i++) {
                System.out.println(arrlIndex.get(i) + " " + arrlValue.get(i));
            }
        }
    }
}