[백준 20920] 영단어 암기는 괴로워 (JAVA)

https://www.acmicpc.net/problem/20920

20920번: 영단어 암기는 괴로워

객체를 만들고, Map과 ArrayList를 사용하여 문제를 해결하였다.

Map의 키는 단어, 값은 단어가 나온 수를 넣는다.

 

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

public class Main {

	static class Word {
		int count;
		String word;

		Word(int count, String word) {
			this.count = count;
			this.word = word;
		}
	}

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(br.readLine());
		int n = Integer.parseInt(st.nextToken());
		int m = Integer.parseInt(st.nextToken());
		ArrayList<Word> arrlist = new ArrayList<>();
		Map<String,Integer> map = new HashMap<>();
		for(int i=0;i<n;i++) {
			String str = br.readLine();
			if(str.length()>=m) {
				map.put(str,map.getOrDefault(str, 0)+1);
			}
		}
		for(String str:map.keySet()) {
			arrlist.add(new Word(map.get(str),str));
		}
		
		Collections.sort(arrlist,(w1,w2)->{
			if(w1.count==w2.count) {
				if(w1.word.length()==w2.word.length()) {
					return w1.word.compareTo(w2.word);
				}else {
					return w2.word.length()-w1.word.length();
				}
			}else {
				return w2.count-w1.count;
			}
		});
		StringBuilder sb = new StringBuilder();
		for(int i=0;i<arrlist.size();i++)
			sb.append(arrlist.get(i).word).append("\n");
		System.out.println(sb);
	}

}