Reverse Words in a String

Description:

Given an input string, reverse the string word by word.

For example,
Given s = "the sky is blue",
return "blue is sky the".

Code:

void reverseWords(string &s) {
        istringstream sstr(s);
        s = "";
        string str;
        while (sstr>>str)
                s = str + ' ' + s;
        if (!s.empty())
            s.erase(s.end()-1);//删除多余的空格
    }