LeetCode:557. Reverse Words in a String III（反转每个单词）

阳光穿透心脏的1/2处 2022-05-08 13:48 161阅读 0赞

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**相关文章：**

1.  **[LeetCode：55. Jump Game（跳远比赛）][LeetCode_55. Jump Game]**
2.  **[Leetcode：300. Longest Increasing Subsequence（最大增长序列）][Leetcode_300. Longest Increasing Subsequence]**
3.  **[LeetCode：560. Subarray Sum Equals K（找出数组中连续子串和等于k）][LeetCode_560. Subarray Sum Equals K_k]**

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**文章目录：**

题目描述：

java实现方法1:

Python实现方法1：

java实现方法2：

Python实现方法2：

源码github地址：

--------------------

### 题目描述： ###

Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.

**Example 1:**

Input: "Let's take LeetCode contest"
    Output: "s'teL ekat edoCteeL tsetnoc"

**Note:** In the string, each word is separated by single space and there will not be any extra space in the string.

--------------------

### java实现方法1: ###

/**
         * 反转字符串
         *
         * @param s 字符串
         * @return 反转字符串
         */
        public String reverseWords(String s) {
            StringBuffer result = new StringBuffer();
            int length = s.length();
            int i = 0;
            while (i < length) {
                int start = i;
                while (i < length && s.charAt(i) != ' ') {
                    i++;
                }
                for (int p = i - 1; p >= start; p--) {
                    result.append(s.charAt(p));
                }
                while (i < length && s.charAt(i) == ' ') {
                    i++;
                    result.append(' ');
                }
            }
            return result.toString();
        }

时间复杂度：O(n)

空间复杂度：O(n)

--------------------

### Python实现方法1： ###

def reverse_words(self, s: str) -> str:
            '''
                单词反转
            Args:
                arr: 字符串
            Returns:
                反转后字符串
            '''
            res = ''
            length = len(s)
            i = 0
            while i < length:
                start = i
                while i < length and s[i] != ' ':
                    i += 1
                for p in range(start, i)[::-1]:
                    res += s[p]
                while i < length and s[i] == ' ':
                    i += 1
                    res += ' '
            return res

时间复杂度：O(n)

空间复杂度：O(n)

--------------------

### java实现方法2： ###

/**
         * 反转字符串
         *
         * @param s 字符串
         * @return 反转字符串
         */
        public String reverseWords2(String s) {
            String[] strings = s.split(" ");
            StringBuilder sb = new StringBuilder();
            for (String sub : strings) {
                sb.append(new StringBuffer(sub).reverse().toString() + " ");
            }
            return sb.toString().trim();
        }

时间复杂度：O(n)

空间复杂度：O(n)

--------------------

### Python实现方法2： ###

def reverse_words2(self, s: str) -> str:
            '''
                单词反转
            Args:
                arr: 字符串
            Returns:
                反转后字符串
            '''
            strs = s.split(' ')
            res = []
            for sub in strs:
                res.append(sub[::-1])
            return ' '.join(res)

时间复杂度：O(n)

空间复杂度：O(n)

--------------------

### 源码github地址： ###

[https://github.com/zhangyu345293721/leetcode][https_github.com_zhangyu345293721_leetcode]

[github]: https://github.com/zhangyu345293721
[LeetCode_55. Jump Game]: https://blog.csdn.net/zy345293721/article/details/84991870
[Leetcode_300. Longest Increasing Subsequence]: https://blog.csdn.net/zy345293721/article/details/84984249
[LeetCode_560. Subarray Sum Equals K_k]: https://blog.csdn.net/zy345293721/article/details/84952201
[https_github.com_zhangyu345293721_leetcode]: https://github.com/zhangyu345293721/leetcode