题解 | #成绩排序#

import java.util.*;

// 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);
        HashMap<Integer, ArrayList<Integer>> map = new HashMap<>();
        int num = in.nextInt();
        int Sort = in.nextInt();
        String[][] str = new String[num + 1][2];
        // 注意 hasNext 和 hasNextLine 的区别
        ArrayList<Integer> Test = new ArrayList<>();
        for (int i = 0; i < num; i++) {
		  //不知道为什么nextLine后用split()无法装入数组中只能选择手动分别装入
            // String r=in.nextLine();
            // str[i] = r.split(" ");
            // String[] p = r.split(" ");
            // System.out.println(in.nextLine());
            // System.out.println(p[0]+"   "+p[1]);
            str[i][0]=in.next();
            str[i][1]=in.next();
            int core = Integer.parseInt(str[i][1]);
            if (!Test.contains(core)) {
                Test.add(core);
            }
            if (!map.containsKey(core)) {
                ArrayList<Integer> list = new ArrayList<>();
                list.add(i);
                map.put(core, list);
            }
            else
            {
                ArrayList<Integer> Update = map.get(core);
                Update.add(i);
            }
        }
        Collections.sort(Test);
        if (Sort != 0)
        {
            
            for (int i = 0; i < Test.size(); i++) {
            ArrayList<Integer> li = map.get(Test.get(i));
                for (int j : li) {
                    System.out.println(str[j][0] + " " + str[j][1]);
                }
            }
        }
        else {
            for (int i = Test.size()-1; i>=0; i--) {
                ArrayList<Integer> li = map.get(Test.get(i));
                for (int j : li) {
                    System.out.println(str[j][0] + " " + str[j][1]);
                }
            }
        }
    }
}