Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.

If the last word does not exist, return 0.

Note: A word is defined as a character sequence consists of non-space characters only.

For example,
Given s = "Hello World",
return 5.

public class Solution {
    public int lengthOfLastWord(String s) {
        int len = s.length();
        int result = 0;
        while(len>0){
            if(s.charAt(len-1) != ' '){
                len--;
                result ++;
            }
            else{
                if(result == 0 && len>0){
                    len --;
                }
                else{
                    return result;
                }                
            }

        }
        return result;
    }
}