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

注意：最后几个字符为连续空格的情况。

class Solution {
public:
    int lengthOfLastWord(const char *s) {
        if(s==" "||s==NULL) return 0;
        int len=strlen(s);
        int time=0;
        if(s[len-1]==' ')
        {
            bool findflag=false;
            for(int i=len-2;i>=0;--i){
                if(s[i]==' '&&!findflag)
                    continue;
                else if(s[i]==' '&&findflag)
                    return time;
                else{
                    ++time;
                    findflag=true;
                }
            }
        }
        else{
            for(int i=len-1;i>=0;--i)
            {
                if(s[i]==' ') return time;
                ++time;
            }
        }
        return time;
    }
};