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.
解题思路：
遍历字符串，设置整形变量n，记录当前遍历到的无空格子串的长度，如果子串后遇到空格，且空格后再次遇到新的子串，则更新n，否则返回n；
附录：
C语言中的char* char const char 和C++ string的关系
【Leetcode】【Easy】Length of Last Word
原文：http://www.cnblogs.com/huxiao-tee/p/4147688.html