151. Reverse Words in a String

原创于 2018-09-02 20:02:38 发布 · 107 阅读

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本文介绍了一种算法，用于将输入字符串中的单词顺序反转。通过去除多余的空格并确保单词间只保留一个空格来实现。提供了Python代码示例。

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

Given an input string, reverse the string word by word.

Example:

Input: "the sky is blue",
Output: "blue is sky the".

Note:

A word is defined as a sequence of non-space characters.
Input string may contain leading or trailing spaces. However, your reversed string should not contain leading or trailing spaces.
You need to reduce multiple spaces between two words to a single space in the reversed string.

Follow up: For C programmers, try to solve it in-place in O(1) space.

class Solution(object):
    def reverseWords(self, s):
        """
        :type s: str
        :rtype: str
        """
        s = s.strip()
        if len(s) == 0:
            return ''
        tmp = [i.strip() for i in s.split(" ")]
        res = []
        for i in range(len(tmp) - 1, -1, -1):
            if len(tmp[i]) > 0:
                res.append(tmp[i])
        return ' '.join(res)