题解 | #二进制取反#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param num string字符串 
     * @return string字符串
     */
    public String maxLexicographical(String num) {
        // write code here
        StringBuffer sb = new StringBuffer("");
        int start = 0;
        int end = 0;
        for (int i = 0; i < num.length(); i++) {
            if (num.charAt(i) == '0') {
                start = i;
                end = i;
                while (end < num.length() && num.charAt(end) == '0') {
                    end++;
                }
                end--;
                break;
            }
        }
        for (int i = 0; i < num.length(); i++) {
            if (num.charAt(i) == '0' && i >= start && i <= end) {
                sb.append("1");
            } else {
                sb.append(num.charAt(i));
            }
        }
        return new String(sb);
    }
}