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.

class Solution {public:    int lengthOfLastWord(const char *s) {        // Start typing your C/C++ solution below        // DO NOT write int main() function        int ret = 0;         int i = strlen(s)-1;                while(i != -1)        {            if(isalpha(*(s+i)))ret++;            else if(ret) break;            i--;        }        return ret;    }};

12 milli secs.