leetcode-study

151. Reverse Words in a String

class Solution:
    def reverseWords(self, s: str) -> str:
        """
        Reverse the order of words in the input string 's'.
        
        Parameters:
            s (str): The input string containing words separated by spaces. This string may include 
                     leading, trailing, or multiple spaces between words.
                     
        Returns:
            str: A string with the words in reverse order, concatenated by a single space.
        """
        # Split 's' into a list of words.
        # The split() method without arguments treats consecutive spaces as a single separator.
        words = s.split()
        
        # Reverse the list of words in-place.
        words.reverse()
        
        # Join the reversed words into one string using a single space as the separator.
        return " ".join(words)

Summary of Techniques and Approaches:

• Leveraging Built-in String Methods:
  The solution uses the split() method to tokenize the string efficiently by automatically discarding extra spaces. This technique is useful when processing text to isolate meaningful components.

• In-place Reversal of a List:
  Reversing the list of words using reverse() is both time-efficient and clean. This approach is applicable in scenarios where the order of elements needs to be manipulated without extra memory overhead.

• Concise String Reassembly:
  The use of join() to reassemble the processed list back into a string exemplifies combining methods to produce concise and readable solutions.

• General Problem-Solving Tips:

  • Identify opportunities to leverage language-specific built-ins for common tasks, such as string manipulation.
  • Look for patterns like tokenization, reversal, or filtering that can simplify the solution.
  • Consider the problem constraints (e.g., extra spaces, mutable vs immutable data structures) to choose the most straightforward and efficient approach.

These techniques can be broadly applied to numerous text processing and array manipulation problems.