557. Reverse Words in a String I

557. Reverse Words in a String III

Easy

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.

把字符串中的每个单词进行翻转，翻转后仍然按照原来的单词顺序进行拼接。

直接分割开每个单词，然后把单词翻转再拼接就好了。

Java

class Solution {
    public String reverseWords(String s) {
        String[] words = s.split(" ");
        StringBuffer ans = new StringBuffer();
        boolean isFirst = true;
        for(String word: words){
            StringBuffer sb = new StringBuffer(word);
            word = sb.reverse().toString();
            if(isFirst){
                ans.append(word);
                isFirst = false;
            }else{
                ans.append(" ");
                ans.append(word);
            }
        }
        return ans.toString();        
    }
}

Python

直接用split将单词切割，然后用 [::-1] 翻转，最后用 join 拼接起来就可以了

class Solution:
    def reverseWords(self, s: str) -> str:
        return " ".join(map(lambda x : x[::-1], s.split(" ")))