leetcode 刷题之路 15 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.

For example, 
Given s = "Hello World",

return 5.

求一个字符串中最后一个单词的长度。这道题比较简单，考虑全面一点，注意临界情况的处理就好。

my accepted answer:

class Solution {public:    int lengthOfLastWord(const char *s)     {        int i=strlen(s)-1;        while(i>=0&&s[i]==' ')            i--;        if (i<0)            return 0;        int len=0;        while(i>=0&&s[i]!=' ')            {                i--;                len++;            }        return len;    }};