How do you solve Capitalize the Title on LeetCode?

Capitalize the Title (LeetCode #2129) 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 the rules for capitalization based on word length is crucial.

What is the brute force solution for Capitalize the Title?

The brute force approach for Capitalize the Title is Brute Force, with O(n²) time complexity and O(1) space complexity. The brute-force approach involves splitting the string into words, checking the length of each word, and then applying the capitalization rules. This is straightforward but inefficient due to repeated string manipulations. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Capitalize the Title?

Capitalize the Title uses the following concepts: String. The recommended patterns to study are: String manipulation, Array processing.

What are the interview tips for Capitalize the Title?

Clarify the problem requirements and constraints before coding. Think about edge cases and how your solution will handle them. Optimize your solution after implementing the brute-force version.

What are common mistakes when solving Capitalize the Title?

Not handling edge cases like single-letter words correctly. Overusing string concatenation in loops, leading to performance issues.

#2129

Capitalize the Title

Easy

StringString manipulationArray processing

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 processes each word in a single pass without unnecessary string manipulations. By using a list to collect results, we can efficiently build the final string.

⚙️

Algorithm

4 steps

1Step 1: Split the input string into words.
2Step 2: Initialize an empty list to store the modified words.
3Step 3: For each word, apply the capitalization rules based on its length and add it to the list.
4Step 4: Join the list into a single string and return it.

solution.py11 lines

1# Full working Python code
2
3def capitalizeTitle(title):
4    words = title.split()
5    result = []
6    for word in words:
7        if len(word) <= 2:
8            result.append(word.lower())
9        else:
10            result.append(word[0].upper() + word[1:].lower())
11    return ' '.join(result)

ℹ

Complexity note: The time complexity is O(n) because we process each character in the string exactly once. The space complexity is O(n) due to the storage of the words in a list before joining them.

1Understanding the rules for capitalization based on word length is crucial.
2Efficient string manipulation can significantly reduce time complexity.

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