[백준] 1235번: 학생 번호 (JAVA)

 

 

 

 

package boj;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.*;

public class Ex1235 {

    public static void main(String[] args) {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
            int n = Integer.parseInt(br.readLine());
            Map<String, Boolean> map = new HashMap<>();
            String[] input = new String[n];
            int result = 0;

            // 학생 수 만큼 문자열 배열에 학생 번호 저장
            for (int i = 0; i < n; i++) {
                input[i] = br.readLine();
            }

            final int hakLen = input[0].length();

            loop:
            for(int i=1; i<=hakLen; i++) {
                for(int j=0; j<n; j++){
                    String hakSub = input[j].substring(hakLen-i);
                    if(map.containsKey(hakSub)) {
                        map.clear();
                        continue loop;
                    } else {
                        map.put(hakSub, true);
                    }
                }
                result = i;
                break;
            }
            System.out.println(result);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}