[BJ1764] 듣보잡

 백준 - 듣보잡 

문제 링크

https://www.acmicpc.net/problem/1764

1764번: 듣보잡

 

문제 입출력

4 3
d
c
b
a
c
b
a

3
a
b
c

 

문제 풀이

package problem.BJ;


import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.StringTokenizer;


public class BJ1764_듣보잡 {
	static int ansN, N, M;
	static Set<String> ds, bs;
	static List<String> ans = new ArrayList<>();


	public static void main(String[] args) throws Exception {
		System.setIn(new FileInputStream("input.txt"));
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		StringTokenizer st = new StringTokenizer(br.readLine());
		N = Integer.parseInt(st.nextToken());
		M = Integer.parseInt(st.nextToken());

		ds = new HashSet<>();
		for (int i = 0; i < N; i++) ds.add(br.readLine());

		bs = new HashSet<>();
		for (int i = 0; i < N; i++) bs.add(br.readLine());

		ds.retainAll(bs); // 교집합 구하기

		// HashSet은 먼저 Collections 으로 변경하고 sorting
		ArrayList<String> dsList = new ArrayList<>(ds);
		Collections.sort(dsList);

		System.out.println(ds.size());
		dsList.forEach(e -> System.out.println(e));

	} // end main
}

 

 

 

 

 

 

 

 

 

 

# 백준 듣보잡 java

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