LintCode-212. 空格替换

输入：string[] = "Mr John Smith" and length = 13
输出：string[] = "Mr%20John%20Smith" and return 17
解释：
对于字符串 "Mr John Smith"，长度为 13。替换空格之后，参数中的字符串需要变为 "Mr%20John%20Smith"，并且把新长度 17 作为结果返回。

输入：string[] = "LintCode and Jiuzhang" and length = 21
输出：string[] = "LintCode%20and%20Jiuzhang" and return 25
解释：
对于字符串 "LintCode and Jiuzhang"，长度为 21。替换空格之后，参数中的字符串需要变为 "LintCode%20and%20Jiuzhang"，并且把新长度 25 作为结果返回。

public class Solution {
    /*
     * @param string: An array of Char
     * @param length: The true length of the string
     * @return: The true length of new string
     */
    public int replaceBlank(char[] string, int length) {
        // write your code here
        // string = String.join("%20", String.valueOf(string).split("\\s")).toCharArray();  
        int index = 0, i, newLength = length;
        for (i = 0; i < length; i++) {
            if (string[i] == 32) {
                index++;
                newLength += 2;
            }
        }
        for (i = length - 1; i >= 0; i--) {
            if (string[i] != 32) {
                string[i + index * 2] = string[i];
            } else {
                string[i] = '%';
                string[i + 1] = '2';
                string[i + 2] = '0';
                i += 3;
                index--;
            }
        }
        return newLength;
    }
}