class Solution {
public:
    string reverseWords(string s) {
        reverse(s.begin(), s.end());
        for (int i = 0; i < s.size(); ++i) {
            int j = i + 1;
            while (j < s.size() && s[j] != ' ') {
                ++j;
            }
            reverse(s.begin() +i, s.begin() + j);
            i = j;
        }
        return s;
    }
};