Leetcode #1592: Rearrange Spaces Between Words
In this guide, we solve Leetcode #1592 Rearrange Spaces Between Words in Python and focus on the core idea that makes the solution efficient.
You will see the intuition, the step-by-step method, and a clean Python implementation you can use in interviews.
Problem Statement
You are given a string text of words that are placed among some number of spaces. Each word consists of one or more lowercase English letters and are separated by at least one space.
Quick Facts
- Difficulty: Easy
- Premium: No
- Tags: String
Intuition
We need to scan characters while tracking positions or counts.
A simple state machine keeps the logic precise.
Approach
Iterate through the string once and update the state for each character.
Use a map or array if you need fast lookups.
Steps:
- Iterate through characters.
- Maintain necessary state.
- Build or validate the output.
Example
Input: text = " this is a sentence "
Output: "this is a sentence"
Explanation: There are a total of 9 spaces and 4 words. We can evenly divide the 9 spaces between the words: 9 / (4-1) = 3 spaces.
Python Solution
class Solution:
def reorderSpaces(self, text: str) -> str:
spaces = text.count(" ")
words = text.split()
if len(words) == 1:
return words[0] + " " * spaces
cnt, mod = divmod(spaces, len(words) - 1)
return (" " * cnt).join(words) + " " * mod
Complexity
The time complexity is , and the space complexity is , where represents the length of the string . The space complexity is , where represents the length of the string .
Edge Cases and Pitfalls
Watch for boundary values, empty inputs, and duplicate values where applicable. If the problem involves ordering or constraints, confirm the invariant is preserved at every step.
Summary
This Python solution focuses on the essential structure of the problem and keeps the implementation interview-friendly while meeting the constraints.