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.

 Notice

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

Example

Given s = "Hello World", return 5.

分析：

First, remove leading and tailing white spaces, and then use a for loop to find the index of the last white space.

实际上，倒着来更好。

public class Solution {
    /**
     * @param s A string
     * @return the length of last word
     */
    public int lengthOfLastWord(String s) {
        // Write your code here
        if (s == null || s.length() == 0) return 0;
        s = s.trim();
        
        int startIndex = 0;
        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == ' ') {
                startIndex = i + 1;
            }
        }
        return s.length() - startIndex;
    }
}