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) {

       s=s.trim();

       int lastIndex=s.lastIndexOf(' ')+1;

       return s.length()-lastIndex;

    }

}