What is the optimal time complexity of solving Merge Two Sorted Lists?

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 Merge Two Sorted Lists?

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 Merge Two Sorted Lists?

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 Merge Two Sorted Lists?

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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Merge Two Sorted Lists

Learn how to solve the 'Merge Two Sorted Lists' problem. This detailed resource details brute force and optimized approaches.

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Problem Statement

Easy

You are given the heads of two sorted linked lists list1 and list2. Merge the two lists into one sorted list. The list should be made by splicing together the nodes of the first two lists. Return the head of the merged linked list.

The linked lists are represented as Python lists. Implement a function mergeTwoLists(list1: list, list2: list) -> list that returns the merged sorted list.

Constraints

•The number of nodes in both lists is in the range [0, 50]
•-100 <= Node.val <= 100
•Both list1 and list2 are sorted in non-decreasing order

Examples

Example 1

Input

[1,2,4], [1,3,4]

Output

[1,1,2,3,4,4]

Explanation

Merging 1->2->4 and 1->3->4 gives 1->1->2->3->4->4.

Example 2

Input

[], []

Output

[]

Explanation

Both lists are empty, so the merged list is also empty.

Example 3

Input

[], [0]

Output

[0]

Explanation

Merging an empty list with [0] gives [0].

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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