[백준] 4575 Refrigerator Magnets - Data Structure / Java

• 문제 링크

4575번: Refrigerator Magnets

 

• 풀이 코드

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.HashSet;
import java.util.Set;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        StringBuilder sb = new StringBuilder();

        String s;
        while (!(s = br.readLine()).equals("END")) {
            if (hasDuplicate(s)) continue;
            sb.append(s).append("\n");
        }

        bw.write(sb.toString());
        bw.flush();
    }

    private static boolean hasDuplicate(String s) {
        Set<Character> set = new HashSet<>();
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c == ' ') continue;
            if (set.contains(c)) return true;
            set.add(c);
        }

        return false;
    }

}