LeetCode 58. 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.

Example:

Input: "Hello World"
Output: 5


这道题简直太简单，面试都考这样的就好了，需要求最后一个单词的长度，如果不存在最后返回0。而且s只存在字母和空格，不存在其他的字符，只需要从后向前遍历数字符就可以了，代码如下：

 1 class Solution {
 2 public:
 3     int lengthOfLastWord(string s) 
 4     {
 5         int len = 0, tail = s.length() - 1;
 6         while (tail >=0 && s[tail] == ‘ ‘)
 7             tail--;
 8         while (tail >=0 && s[tail] != ‘ ‘)
 9         {
10             tail--;
11             len++;
12         }
13         return len;
14     }
15 };