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.
思路： 两根指针
（1） 先从右往左判断是否有空
（2）移动左指针
（3） 右指针 - 左指针
public class Solution {
public int lengthOfLastWord(String s) {
if(s == null || s.length() == 0) {
return 0;
}
int start = 0;
int end = s.length() - 1;
while(end >= 0 && s.charAt(end) == ‘ ‘) {
end --;
}
start = end;
while(start >= 0 && s.charAt(start) != ‘ ‘) {
start--;
}
return end - start ;
}
}
leetcode : Length of Last Word [基本功]
原文：http://www.cnblogs.com/superzhaochao/p/6475911.html