How do you solve Sorting the Sentence on LeetCode?

Sorting the Sentence (LeetCode #1859) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(n) space complexity. Key insight: Understanding how to manipulate strings and extract information is crucial.

What is the brute force solution for Sorting the Sentence?

The brute force approach for Sorting the Sentence is Brute Force, with O(n²) time complexity and O(1) space complexity. The brute-force approach involves splitting the sentence into words, sorting them based on their appended index, and then reconstructing the original sentence. It's straightforward but inefficient due to the sorting step. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Sorting the Sentence?

Sorting the Sentence uses the following concepts: String, Sorting. The recommended patterns to study are: Array, String Manipulation.

What are the interview tips for Sorting the Sentence?

Always clarify the problem requirements and constraints before jumping to a solution. Think about edge cases, such as the minimum and maximum number of words. Practice explaining your thought process as you code; it helps in interviews.

What are common mistakes when solving Sorting the Sentence?

Forgetting to convert the character index to an integer. Not properly handling the string manipulation when reconstructing the original sentence.

#1859

Sorting the Sentence

Easy

StringSortingArrayString Manipulation

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n)
Space	O(1)	O(n)

💡

Intuition

Time O(n)Space O(n)

The optimal approach uses a single pass to place each word in its correct position based on the index, which is more efficient than sorting.

⚙️

Algorithm

4 steps

1Step 1: Split the input string into words using space as a delimiter.
2Step 2: Create an array of the same length as the number of words to hold the original words in their correct positions.
3Step 3: For each word, extract the index and place the word in the correct position in the array.
4Step 4: Join the array into a single string to form the original sentence.

solution.py9 lines

1# Full working Python code
2s = 'is2 sentence4 This1 a3'
3words = s.split()
4original_words = [''] * len(words)
5for word in words:
6    index = int(word[-1]) - 1
7    original_words[index] = word[:-1]
8original_sentence = ' '.join(original_words)
9print(original_sentence)

ℹ

Complexity note: The time complexity is O(n) because we only make a single pass through the words. The space complexity is O(n) due to the storage of the original words in an array.

1Understanding how to manipulate strings and extract information is crucial.
2Recognizing the need for sorting or indexing can lead to more efficient solutions.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.