Problem

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.

My Solution

public class Solution {

    public static int lengthOfLastWord(String s) {
        s = s.trim(); // 去掉字符串首尾的空格
        int i = 0;
        for (i = s.length() - 1; i >= 0; --i) {
            if (s.substring(i, i + 1).equals(" ")) {
                return s.length() - i - 1;
            }
        }
        return s.length();
    }

Great Solution

public int lengthOfLastWord(String s) {
    return s.trim().length()-s.trim().lastIndexOf(" ")-1;
}