Space Replacement

Write a method to replace all spaces in a string with %20. The string is given in a characters array, you can assume it has enough space for replacement and you are given the true length of the string.

Have you met this question in a real interview?

Yes

Example

Given "Mr John Smith", length = 13.

The string after replacement should be "Mr%20John%20Smith".

Note

If you are using Java or Python，please use characters array instead of string.

Challenge

Do it in-place.

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
        if(string == null || length <= 0) return 0;
        int spaceCount = 0;
        for(char c : string){
            if(c == ' ') spaceCount+=2;
        }
        int lastIdx = length + spaceCount - 1;
        for(int i = length - 1; i >= 0; i--){
            if(string[i] == ' '){
                string[lastIdx--] = '0';
                string[lastIdx--] = '2';
                string[lastIdx--] = '%';
            }else{
                string[lastIdx--] = string[i];
            }
        }
        return length + spaceCount;
       
    }
}