Good afternoon! Here's our prompt for today.

Now that we've implemented a Linked List, let's start operating on it! Assume you have a Linked List implementation with this definition:

1class LinkedList {
2	constructor() {
3		this.head = null;
4		this.tail = null;
5	}
6
7	prepend(newVal) {
8		const currentHead = this.head;
9		const newNode = new Node(newVal);
10		newNode.next = currentHead;
11		this.head = newNode;
12
13		if (!this.tail) {
14			this.tail = newNode;
15		}
16	}
17
18	append(newVal) {
19		const newNode = new Node(newVal);
20		if (!this.head) {
21			this.head = newNode;
22			this.tail = newNode;
23		} else {
24			this.tail.next = newNode;
25			this.tail = newNode;
26		}
27	}
28}

Can you write a method getUnion to find the union of two linked lists? A union of two sets includes everything in both sets.

So given 1 -> 2 -> 3 and 3 -> 4 -> 5, we'd get 1 -> 2 -> 3 -> 4 -> 5.

Constraints

• Length of both the linkedlist <= 1000
• The nodes will always contain integer values between -1000000000 and 1000000000
• Let m, n be the lengths of the two lists
• Expected time complexity : O(n*m)
• Expected space complexity : O(n+m)

Try to solve this here or in Interactive Mode.

How do I practice this challenge?

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    'PASSED: Expected the following: `let list1 = new LinkedList; list1.prepend(25); list1.prepend(15); list1.prepend(5); list1.prepend(9);  let list2 = new LinkedList; list2.prepend(14); list2.prepend(15); list2.prepend(7); list2.prepend(13); getUnion(list1, list2).toArray();`to have members `[13, 7, 14, 25, 15, 5, 9]`'

function getUnion(list1, list2) {

  // implement a method to get the union

}

​

function Node(val) {

  this.val = val;

  this.next = null;

}

​

class LinkedList {

  constructor() {

    this.head = null;

    this.tail = null;

  }

​

  prepend(newVal) {

    const currentHead = this.head;

    const newNode = new Node(newVal);

    newNode.next = currentHead;

    this.head = newNode;

​

    if (!this.tail) {

      this.tail = newNode;

    }

  }

​

  append(newVal) {

    const newNode = new Node(newVal);

    if (!this.head) {

Here's our guided, illustrated walk-through.

How do I use this guide?