学步园

class Solution {
public:
    int lengthOfLastWord(const char *s) {
        const char *p = s;
        if( p == NULL)
            return 0;
        int len = 0;
        while( (*p) != '\0')
        {
            len ++;
            p++;
        }
        
        int last_len = 0;
        int flag = 0;
        for(int i=len-1; i>=0; i--)
        {
            if(s[i] == ' ' && flag == 0)
                ;
            else if(s[i] == ' ' && flag == 1)
                return last_len;
            else
            {
                if( flag == 0 )
                    flag = 1;
                last_len++;
            }
        }
        
        return last_len;
        
    }
};