Introduction

In this blog post, we will explore how to solve the LeetCode problem "1451" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like Chatmagic, we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

Problem Statement

Given a sentence text (A sentence is a string of space-separated words) in the following format: First letter is in upper case. Each word in text are separated by a single space. Your task is to rearrange the words in text such that all words are rearranged in an increasing order of their lengths. If two words have the same length, arrange them in their original order. Return the new text following the format shown above. Example 1: Input: text = "Leetcode is cool" Output: "Is cool leetcode" Explanation: There are 3 words, "Leetcode" of length 8, "is" of length 2 and "cool" of length 4. Output is ordered by length and the new first word starts with capital letter. Example 2: Input: text = "Keep calm and code on" Output: "On and keep calm code" Explanation: Output is ordered as follows: "On" 2 letters. "and" 3 letters. "keep" 4 letters in case of tie order by position in original text. "calm" 4 letters. "code" 4 letters. Example 3: Input: text = "To be or not to be" Output: "To be or to be not" Constraints: text begins with a capital letter and then contains lowercase letters and single space between words. 1 <= text.length <= 10^5

Explanation

Here's the breakdown of the approach, complexity, and the Python code:

• Approach:

  1. Split the input sentence into a list of words.
  2. Sort the list of words based on their lengths, preserving the original order for words with the same length.
  3. Reconstruct the sentence from the sorted words, capitalizing the first word and converting the rest to lowercase.

• Complexity:

  • Runtime Complexity: O(N log N), where N is the number of words in the input sentence (due to sorting).
  • Storage Complexity: O(N), where N is the number of words (to store the list of words and the reconstructed sentence).

Code

    def arrange_words(text: str) -> str:
    """
    Rearranges the words in a sentence based on their lengths in increasing order.

    Args:
        text: The input sentence.

    Returns:
        The rearranged sentence.
    """

    words = text.split()
    words[0] = words[0].lower()  # lowercase the first word since sorting changes its position
    words.sort(key=len)

    result = " ".join(words)
    result = result[0].upper() + result[1:]  # Capitalize the first letter

    return result