README_EN.md

557. Reverse Words in a String III

中文文档

Description

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

 

Example 1:

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

Example 2:

Input: s = "God Ding"
Output: "doG gniD"

 

Constraints:

• 1 <= s.length <= 5 * 104
• s contains printable ASCII characters.
• s does not contain any leading or trailing spaces.
• There is at least one word in s.
• All the words in s are separated by a single space.

Solutions

Python3

class Solution:
    def reverseWords(self, s: str) -> str:
        return ' '.join([t[::-1] for t in s.split(' ')])

Java

class Solution {
    public String reverseWords(String s) {
        StringBuilder res = new StringBuilder();
        for (String t : s.split(" ")) {
            for (int i = t.length() - 1; i >= 0; --i) {
                res.append(t.charAt(i));
            }
            res.append(" ");
        }
        return res.substring(0, res.length() - 1);
    }
}

C++

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

Go

func reverseWords(s string) string {
	t := []byte(s)
	for i := 0; i < len(t); i++ {
		j := i
		for j < len(t) && t[j] != ' ' {
			j++
		}
		for st, ed := i, j-1; st < ed; st, ed = st+1, ed-1 {
			t[st], t[ed] = t[ed], t[st]
		}
		i = j
	}
	return string(t)
}

TypeScript

function reverseWords(s: string): string {
    return s
        .split(/\s+/)
        .map(str => {
            let res = '';
            for (const c of str) {
                res = c + res;
            }
            return res;
        })
        .join(' ');
}

Rust

impl Solution {
    pub fn reverse_words(s: String) -> String {
        s.split(' ')
            .map(|s| s.chars().rev().collect::<String>())
            .collect::<Vec<_>>()
            .join(" ")
    }
}

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