[Codetree] 이상한 진수 2

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        // Please write your code here.
        int n = a.length();
        int[] arr = new int[n];
        for(int i = 0; i < n; i++){
            arr[i] = a.charAt(i)-'0';
        }        

        int max = Integer.MIN_VALUE;
        for(int i = 0; i < n; i++) {
            arr[i] = reverse(arr[i]); // 한자리만 반전
            max = Math.max(max,getDecimal(arr)); // 최대값
            arr[i] = reverse(arr[i]); // 해당자리 원상복구
        }        
        System.out.println(max);
    }
    public static int reverse(int num) {        
        if(num == 0) return 1;
        return 0;
    }

    public static int getDecimal(int[] arr) {
        int digit = 1, sum = 0;
        for(int i = arr.length - 1; i >= 0; i--) {
            sum+= digit*arr[i];
            digit = digit*2;
        }
        return sum;
    }
}