What is the optimal time complexity of solving Valid Parenthesis String?

The optimized solution achieves a time complexity of O(n) by using sorting, mathematical shortcuts, or hash table lookups.

What is the auxiliary space complexity for Valid Parenthesis String?

The space complexity is O(n) since we only use a minimal/constant amount of extra memory for tracking variables (or auxiliary space if dynamic structures are allocated).

What are the typical edge cases we must handle in Valid Parenthesis String?

Key edge cases include empty collections, negative or large bounds causing integer overflow, arrays with only one element, or inputs where target criteria are not met.

How can we optimize the brute force approach for Valid Parenthesis String?

Brute force methods often inspect all possible combinations. We optimize this by sorting the input list to enable binary search, or tracking processed items in a set to avoid redundant nested loop lookups.

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Valid Parenthesis String

Learn how to solve the 'Valid Parenthesis String' problem. This detailed resource details brute force and optimized approaches.

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Problem Statement

Easy

Given a string s containing only three types of characters: '(', ')' and '*', return True if s is valid.

The following rules define a valid string:

- Any left parenthesis '(' must have a corresponding right parenthesis ')'.

- Any right parenthesis ')' must have a corresponding left parenthesis '('.

- Left parenthesis '(' must go before the corresponding right parenthesis ')'.

- '*' could be treated as a single right parenthesis ')' or a single left parenthesis '(' or an empty string.

Write a function checkValidString(s: str) -> bool.

Constraints

•1 <= len(s) <= 100
•s contains only '(', ')' and '*'

Examples

Example 1

Input

s = "()"

Output

True

Explanation

Matches perfectly.

Example 2

Input

s = "(*)"

Output

True

Explanation

Treat '*' as empty string.

Example 3

Input

s = "(*))"

Output

True

Explanation

Treat '*' as '('.

Need a Hint?

Analyze the input constraints. Try sorting first (O(n log n)) or using a hash map/set to track seen elements in O(n) time.

Edge Cases to Watch

Empty list or null input variables
Single item lists/arrays
Extremely large input bounds causing integer or stack overflow

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