Linked List Intersection

Determine if two singly linked lists intersect and return the intersecting node. This problem tests your understanding of linked list manipulation and efficient algorithm design.

linked-listtwo-pointersintersectiondata-structures

Problem Statement

Given the head nodes of two singly linked lists, determine if the two lists intersect. If they do, return the reference to the intersecting node. Note that intersection is by reference, not by value. If the lists do not intersect, return None.

Example 1

Input: list1: 1 -> 3 -> 5 -> 7 -> 9 -> 11; list2: 2 -> 4 -> 5 -> 7 -> 9 -> 11

Output: Node with value 5

The two linked lists intersect at the node with value 5. From that point onwards, they share the same nodes.

Example 2

Input: list1: 1 -> 2 -> 3; list2: 4 -> 5 -> 6

Output: None

The two linked lists do not intersect at any point. They are completely separate.

Constraints

-The linked lists are singly linked.
-The values in the nodes can be any integer.
-The lists may or may not have the same length.
-The lists can be empty.
-The number of nodes in each list is between 0 and 1000.

Brute Force Approach

The brute force approach would be like checking every possible meeting point between two roads. You'd iterate through each node in the first list and compare it to every node in the second list, looking for a matching reference. This is inefficient because you are doing a lot of redundant comparisons.

TimeO(m*n)

SpaceO(1)

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