151. Reverse Words in a String

class Solution {
public:
    void reverseS(string &s, int i, int j){
      while(i<j)
      {
        swap(s[i], s[j]);
        i++;
        j--;
      }
    }

    

    string reverseWords(string s) 
    {
        string st;

        reverse(s.begin(), s.end());
      
      int l = 0;

      //remove extra spaces

      bool extra = false;

      for(int i=0; i<s.length(); i++)
      {
           if(s[i] == ' ')
           {
               if(extra == false)
               {
                   continue;
               }
               else
                    st+=s[i];
               extra = false;
           }
           else
           {
               st += s[i];
               extra = true;
           }


      }



      //reversing all the words  when we get a space
      for(int i=0; i<st.length(); i++)
      {
        if(st[i] == ' ')
        {
          reverseS(st, l, i-1);
          l = i+1;
        }
      }

      reverseS(st, l, st.length()-1);

      if(st[st.length() -1] == ' ')
        st.pop_back();

      return st;  
    }
};