문제(출처: https://www.acmicpc.net/problem/13211) 문제 풀이 HashSet을 사용한다. my solution (Java)import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.util.HashSet;import java.util.Set;public class _13211_ { // Passport Checking public static void main(String[] args) throws IOException { BufferedReader bf = new BufferedReader(new InputStreamReader(System.in..
