Reverse Words In String

• Time : O(n)
• Space : O(n)

using namespace std;
string parse(string& s, int& p, bool space) {
	string res = "";
	while(p < s.length() and (s[p] == ' ') == space) {
		res.push_back(s[p++]);
	}
	return res;
}
string reverseWordsInString(string str) {
	if(str.length() == 0) return "";
  vector<string> tokens;
	int p = 0;
	bool space = str[0] == ' ';
	while(p < str.length()) {
		tokens.push_back(parse(str, p, space));
		tokens.push_back(parse(str, p, !space));
	}
	reverse(begin(tokens), end(tokens));
	string res = "";
	for(auto& t : tokens) {
		res += t;
	}
  return res;
}