[백준][Java] 1212번 8진수 2진수 (문자열)

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
 
 
public class Main {
        
    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    private static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
    
    
    private static String[] first = {
            "0", "1", "10", "11", "100", "101", "110", "111"
    };
    private static String[] temp = {
            "000", "001", "010", "011", "100", "101", "110", "111"
    };
    
    
    public static void main(String[] args) throws IOException{
        
        char[] strChar = br.readLine().toCharArray();
        
        StringBuilder resBuilder = new StringBuilder();
        resBuilder.append(first[strChar[0]-'0']);
        
        for(int i=1; i<strChar.length; i++) {
            resBuilder.append(temp[strChar[i]-'0']);
        }
        System.out.println(resBuilder.toString());
        
//        bw.write("");
//        bw.flush();
//        bw.close();
        
            
        
    }
    
//    private static int stoi(String input) {
//        return Integer.parseInt(input);
//    }
    
}