151. Reverse Words in a String

Problem Statement

link: https://leetcode.com/problems/reverse-words-in-a-string/ https://leetcode.cn/problems/reverse-words-in-a-string/

Given an input string s, reverse the order of the words.

A word is defined as a sequence of non-space characters. The words in s will be separated by at least one space.

Return a string of the words in reverse order concatenated by a single space.

Note that s may contain leading or trailing spaces or multiple spaces between two words. The returned string should only have a single space separating the words. Do not include any extra spaces.

Example:

Input: s = "the sky is blue" Output: "blue is sky the"

Input: s = " hello world " Output: "world hello"

Input: s = "a good example" Output: "example good a"

Solution Approach

The solution uses string manipulation methods to reverse the words while maintaining their order and removing extra spaces.

Algorithm

1. Splitting the String: Use Python’s split method, which naturally discards any leading, trailing, or multiple spaces between words and splits the string into words.
2. Reversing the Words: Reverse the list of words obtained in the previous step.
3. Joining the Words: Join the reversed list of words using a space to form the final reversed string.

Implement

    class Solution:
  def reverseWords(self, s: str) -> str:
      l = s.split()
      l.reverse()
      return " ".join(l)
    

    
    

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