What is the optimal time complexity of solving Interleaving 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 Interleaving String?

The space complexity is O(1) 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 Interleaving 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 Interleaving 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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Interleaving String

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

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Problem Statement

Medium

Given strings s1, s2, and s3, find whether s3 is formed by an interleaving of s1 and s2.

An interleaving of two strings s and t is a configuration where they are divided into non-empty substrings such that s = s1 + s2 + ... + sn, t = t1 + t2 + ... + tm, |n - m| <= 1, and the interleaved string is s1 + t1 + s2 + t2 + ... or t1 + s1 + t2 + s2 + ...

Write a function isInterleave(s1: str, s2: str, s3: str) -> bool.

Constraints

•0 <= len(s1), len(s2) <= 100
•0 <= len(s3) <= 200
•s1, s2, and s3 consist of lowercase English letters

Examples

Example 1

Input

s1 = "aabcc", s2 = "dbbca", s3 = "aadbbcbcac"

Output

True

Explanation

aadbbcbcac can be formed by interleaving "aabcc" and "dbbca".

Example 2

Input

s1 = "aabcc", s2 = "dbbca", s3 = "aadbbbaccc"

Output

False

Explanation

It is impossible to interleave s1 and s2 to obtain s3.

Need a Hint?

Define subproblem states, establish the recurrence relation, and use memoization (top-down) or tabulation (bottom-up).

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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