How do you solve Minimize String Length on LeetCode?

Minimize String Length (LeetCode #2716) 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: The minimized string will contain all distinct characters of the original string.

What is the brute force solution for Minimize String Length?

The brute force approach for Minimize String Length is Brute Force, with O(n²) time complexity and O(n) space complexity. The brute-force approach involves checking each character and removing duplicates by scanning the string multiple times. This is straightforward but inefficient as it requires repeated passes through the string. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Minimize String Length?

Minimize String Length uses the following concepts: Hash Table, String. The recommended patterns to study are: Hash Map, Set.

What are the interview tips for Minimize String Length?

Always consider the simplest approach first, even if it's inefficient. Think about data structures that can help simplify the problem, like sets for uniqueness. Practice explaining your thought process clearly, as communication is key in interviews.

What are common mistakes when solving Minimize String Length?

Not using a data structure that automatically handles duplicates, like a HashSet. Overcomplicating the problem by trying to simulate deletions instead of focusing on unique characters.

#2716

Minimize String Length

Easy

Hash TableStringHash MapSet

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

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

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Intuition

Time O(n)Space O(n)

The optimal solution uses a HashSet to track unique characters efficiently, allowing us to determine the minimized string length in a single pass through the input string.

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Algorithm

4 steps

1Step 1: Initialize an empty HashSet to keep track of unique characters.
2Step 2: Iterate through each character in the string.
3Step 3: Add each character to the HashSet (duplicates will be ignored automatically).
4Step 4: Return the size of the HashSet as the minimized string length.

solution.py2 lines

1def minimize_string_length(s):
2    return len(set(s))

ℹ

Complexity note: The time complexity is O(n) because we make a single pass through the string to add characters to the HashSet. The space complexity is O(n) due to the storage of unique characters.

1The minimized string will contain all distinct characters of the original string.
2Using a HashSet allows for efficient duplicate checking.

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