Length of Last Word

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.

Solution

public class Solution {
    public int lengthOfLastWord(String s) {
        int res = 0, i = s.length() - 1;
        while (i >= 0 && s.charAt(i) == ' ') --i;
        while (i >= 0 && s.charAt(i) != ' ') {
            --i; ++res;
        }
        return res;
    }
}