题解 | #HJ008 合并表记录#

import java.util.*;

/**
 * HJ8 合并表记录
 */
public class HJ008 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        TreeMap<Integer, Integer> map = new TreeMap<>(); // 输出结果要求有序！
        while (sc.hasNextInt()) {
            int n = sc.nextInt();
            for (int i = 0; i < n; ++i) {
                int a = sc.nextInt();
                int b = sc.nextInt();
                map.put(a, map.getOrDefault(a, 0) + b);
            }
        }
        for (Integer i : map.keySet()) {
            System.out.println(i + " " + map.get(i));
        }
        sc.close();
    }

}