没看答案，先遍历s把单词提取出来到列表里，然后再组合成符合要求的答案。

class Solution:
    def reverseWords(self, s: str) -> str:
        i, ls = 0, []

        while i < len(s):
            if s[i] != ' ':
                tmp = ''
                while i < len(s) and s[i] != ' ':
                    tmp += s[i]
                    i += 1
                ls.append(tmp)
            else:
                i += 1
        
        res = ' '.join(ls[::-1])

        return res