Linked List Components

Problem Description

You are given the head of a linked list containing unique integer values and an integer array nums that is a subset of the linked list values. Return the number of connected components in nums where two values are connected if they appear consecutively in the linked list.

Key Insights

• A connected component is defined by consecutive nodes in the linked list that are also present in the nums array.
• We can utilize a set data structure for fast membership testing of the nums values.
• We traverse the linked list and count the number of times we encounter a value in nums that is followed by another value also in nums.

Space and Time Complexity

Time Complexity: O(n), where n is the number of nodes in the linked list.
Space Complexity: O(m), where m is the number of elements in nums (due to the set used for membership testing).

Solution

To solve the problem, we will:

1. Convert the nums array into a set for O(1) time complexity when checking for membership.
2. Traverse the linked list node by node.
3. For each node, check if its value is in the nums set. If it is, check if the next node's value is also in the nums set.
4. Count each distinct group of connected components as we find them.

Code Solutions