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.

For example, 
Given s = "Hello World",
return 5.

class Solution {
public:
    int lengthOfLastWord(const char *s) {
        if (strlen(s)<=0)
            return 0;
        int pos = strlen(s)-1;
        int count=0;
        for (;pos>=0;pos--)
        {
            if (s[pos]==' ')
            {
                if (count==0)   
                    continue;
                return count;
            }
            else
            {
                count++;
            }
        }
        return count;
    }
};