Im tryna solve this problem:

https://leetcode.com/problems/reverse-words-in-a-string/description/

with this code::

class Solution {
public:
    string reverseWords(string s) {
        stack <string> stk;
        string str;
        string word = "";

        for(int i =0 ;i < (int) s.size(); i++){
            if(s[i]!=' ') {
                word +=s[i];
            }else{
                stk.push(word);
                word = "";
            }
        }
        str = stk.top();
        stk.pop();
        while(!stk.empty()){
            str += ' ' + stk.top();
            stk.pop();
        }

        return str;
    }
};

s = "the sky is blue"

and the expected outcome is: "blue is sky the"
mine is :: "is sky the"

please help!