557. Reverse Words in a String III

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 = "Mr Ding"
Output: "rM 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

Solution 1

Python Code
1
2
3

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

Java Code
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12

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++ Code
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13

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 Code
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14

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 Code
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12

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 Code
1
2
3
4
5
6
7
8

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

PHP Code
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13

class Solution {
    /**
     * @param String $s
     * @return String
     */
    function reverseWords($s) {
        $sArr = explode(' ', $s);
        for ($i = 0; $i < count($sArr); $i++) {
            $sArr[$i] = strrev($sArr[$i]);
        }
        return implode(' ', $sArr);
    }
}