Question

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 = "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

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

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);
  }
}

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;
  }
};

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)
}

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

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

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);
  }
}