Length of Last Word

class Solution {public:    int lengthOfLastWord(string s)     {        if(s.empty())            return 0;        int count=0;        bool firstspace=true;        const int n=s.size();        for(int i=n-1;i>=0;--i)        {            if(s[i]!=' ')            {                 ++count;                 firstspace=false;            }               if(s[i]==' '&& firstspace)                continue;            if(s[i]==' '&& !firstspace)                return count;                    }        return count;                    }};