201709-2 公共鑰匙盒

我覺得是第二題裏面最難的，然後這次認證的第三題也是我覺得最難的😂，不過好像第四題和第五題可以騙點分。

用TreeMap來存儲所有的時間點及該時間點要還和要借的鑰匙，其中不論是借的還是還的鑰匙也用TreeSet來存。這些都是爲了達到排序的效果。思路就是遍歷時間點，每個時間點先還鑰匙，然後借鑰匙。

奉上java滿分代碼

import java.util.*;

public class Main{
    static class TimeSection{
        public TreeSet<Integer> getKeys = new TreeSet<>();
        public TreeSet<Integer> bacKeys = new TreeSet<>();
    }

    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in);
        String[] firstLine = scanner.nextLine().split(" ");
        int n = Integer.parseInt(firstLine[0]);
        int k = Integer.parseInt(firstLine[1]);
        List<Integer> keys = new ArrayList<>();
        for(int i = 0; i < n; i++){
            keys.add(i + 1);
        }
        TreeMap<Integer, TimeSection> map = new TreeMap<>();
        for(int i = 0; i < k; i++){
            String[] data = scanner.nextLine().split(" ");
            int key = Integer.parseInt(data[0]);
            int start = Integer.parseInt(data[1]);
            int end = Integer.parseInt(data[2]) + start;
            {
                TimeSection startSection = new TimeSection();
                if(map.containsKey(start)){
                    startSection = map.get(start);
                }
                startSection.getKeys.add(key);
                map.put(start, startSection);
            }
            {
                TimeSection endSection = new TimeSection();
                if(map.containsKey(end)){
                    endSection = map.get(end);
                }
                endSection.bacKeys.add(key);
                map.put(end, endSection);
            }
        }
        scanner.close();

        for(Iterator<Integer> iterator = map.keySet().iterator(); iterator.hasNext();){
            TimeSection timeSection = map.get(iterator.next());
            for(int key : timeSection.bacKeys){
                for(int i = 0; i < keys.size(); i++){
                    if(keys.get(i) == -1){
                        keys.set(i, key);
                        break;
                    }
                }
            }
            for(int key : timeSection.getKeys){
                for(int i = 0; i < keys.size(); i++){
                    if(keys.get(i) == key){
                        keys.set(i, -1);
                        break;
                    }
                }
            }
        }

        for(int key : keys){
            System.out.print(key + " ");
        }
    }
}