Wonderland
  • README.md
  • Notebook
    • Crypto
      • Solana
        • Troubleshooting
          • BPF SDK path does not exist
    • Language
      • Rust
        • Reference
          • Capturing the Environment with Closures
          • Understanding &mut &mut Reference
      • C++
        • Reference
          • Code for MS rand() and srand() in VC++ 6.0
  • Textbook
    • Serials
      • A Real-Time Cryptocurrency Ticker Dashboard
        • 0 - Some Preparation
    • Frontend
      • A Simple Progress Bar
      • A React Ribbon Component
      • An Easy to Use React DnD Sortable Component
      • Sticky Header, Sticky Footer and Fluid Content
      • How To Set Same Height As Width In CSS
  • dictionary
    • Alphabet
      • MySQL
      • FFmpeg
    • Algorithm
      • Diary
        • 2022
          • 07
            • 2022-07-02
            • 2022-07-01
          • 06
            • 2022-06-30
            • 2022-06-29
            • 2022-06-28
            • 2022-06-27
            • 2022-06-26
            • 2022-06-25
            • 2022-06-24
            • 2022-06-23
            • 2022-06-22
            • 2022-06-21
            • 2022-06-20
            • 2022-06-19
            • 2022-06-18
            • 2022-06-17
            • 2022-06-16
            • 2022-06-15
            • 2022-06-14
            • 2022-06-13
            • 2022-06-12
            • 2022-06-11
            • 2022-06-10
            • 2022-06-09
            • 2022-06-08
            • 2022-06-07
            • 2022-06-06
            • 2022-06-05
            • 2022-06-04
            • 2022-06-03
            • 2022-06-02
            • 2022-06-01
          • 05
            • 2022-05-31
            • 2022-05-30
            • 2022-05-29
            • 2022-05-28
            • 2022-05-27
            • 2022-05-26
            • 2022-05-25
            • 2022-05-24
            • 2022-05-23
            • 2022-05-22
            • 2022-05-21
            • 2022-05-20
            • 2022-05-19
            • 2022-05-18
            • 2022-05-17
            • 2022-05-16
            • 2022-05-15
    • Troubleshooting
      • A Weird Python Command Not Found Problem
Powered by GitBook
On this page
  • 344. Reverse String
  • Description
  • Solution
  • 557. Reverse Words in a String III
  • Description
  • Solution
  1. dictionary
  2. Algorithm
  3. Diary
  4. 2022
  5. 05

2022-05-18

Last updated 2 years ago

Description

Write a function that reverses a string. The input string is given as an array of characters s.

You must do this by modifying the input array with O(1) extra memory.

Example 1:

Input: s = ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]

Example 2:

Input: s = ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]

Constraints:

  • 1 <= s.length <= 105

  • s[i] is a .

Solution

func reverseString(s []byte) {
    for i, j := 0, len(s)-1; i < j; {
        s[i], s[j] = s[j], s[i]
        i++
        j--
    }
}

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.

Solution

Approach #0

func reverseWord(s []rune) string {
    for i, j := 0, len(s)-1; i < j; {
        s[i], s[j] = s[j], s[i]
        i++
        j--
    }
    return string(s)
}

func reverseWords(s string) string {
    sList := strings.Split(s, " ")
    var res []string
    for _, aS := range sList {
        res = append(res, reverseWord([]rune(aS)))
    }
    return strings.Join(res, " ")
}

Approach #1

func reverseWord(s []rune) {
    for i, j := 0, len(s)-1; i < j; {
        s[i], s[j] = s[j], s[i]
        i++
        j--
    }
}

func reverseWords(s string) string {
    r := []rune(s)
    l := 0
    for i, letter := range r {
        if string(letter) == " " {
            reverseWord(r[l:i])
            l = i + 1
        }
    }
    reverseWord(r[l:])
    return string(r)
}

344. Reverse String
in-place
printable ascii character
557. Reverse Words in a String III