1var assert = require('assert');
2
3function Node(val, next, random) {
4    this.val = val;
5    this.next = next;
6    this.random = random;
7};
8
9function cloneRandomList(head) {
10    if (head === null) {
11        return null;
12    }
13
14    let currentNode = head;
15    while (currentNode) {
16        let temp = new Node(currentNode.val);
17        temp.next = currentNode.next;
18        currentNode.next = temp;
19        currentNode = currentNode.next.next;
20    }
21
22    currentNode = head;
23    while (currentNode) {
24        if (currentNode.random) {
25            currentNode.next.random = currentNode.random.next;
26        } else {
27            currentNode.next.random = null;
28        }
29        currentNode = currentNode.next.next;
30    }
31
32    currentNode = head;
33    let copyHead = head.next;
34    while (currentNode.next) {
35        temp = currentNode.next;
36        currentNode.next = currentNode.next.next;
37        currentNode = temp;
38    }
39    return copyHead;
40}
41
42
43try {
44    let head = new Node(1);
45    head.next = new Node(2);
46    head.random = head.next;
47    head.next.next = null;
48    head.next.random = head.next;
49    let lst, random = listToString(head);
50    let lstAns, randomAns = listToString(cloneRandomList(head));
51    assert.equal(lst, lstAns);
52    assert.equal(random, randomAns);
53    console.log('PASSED: ' + "`cloneRandomList([[1, 1],[2, 1]]) should return `[[1, 1],[2, 1]]`");
54} catch (err) {
55    console.log(err);
56}
57
58try {
59    let head = new Node(3);
60    head.next = new Node(3);
61    head.random = null;
62    head.next.next = new Node(3);
63    head.next.random = head;
64    head.next.next.next = null;
65    head.next.next.random = null;
66    let lst, random = listToString(head);
67    let lstAns, randomAns = listToString(cloneRandomList(head));
68    assert.equal(lst, lstAns);
69    assert.equal(random, randomAns);
70    console.log('PASSED: ' + "`cloneRandomList([[3, null], [3, 0], [3, null]]) should return `[[3, null], [3, 0], [3, null]]`");
71} catch (err) {
72    console.log(err);
73}
74
75try {
76    let head = new Node(7);
77    head.next = new Node(13);
78    head.next.next = new Node(11);
79    head.next.next.next = new Node(10);
80    head.next.next.next.next = new Node(1);
81    head.random = null;
82    head.next.random = head;
83    head.next.next.random = head.next.next.next.next;
84    head.next.next.next.random = head.next.next;
85    head.next.next.next.next.random = head;
86    let lst, random = listToString(head);
87    let lstAns, randomAns = listToString(cloneRandomList(head));
88    assert.equal(lst, lstAns);
89    assert.equal(random, randomAns);
90    console.log('PASSED: ' + "`cloneRandomList([[7, null], [13, 0], [11, 4], [10, 2], [1, 0]]) should return `[[7, null], [13, 0], [11, 4], [10, 2], [1, 0]]`");
91} catch (err) {
92    console.log(err);
93}
94
95function listToString(head) {
96    var toPrint = [];
97    var toPrintRandom = [];
98    var currNode = head;
99    while (currNode) {
100        toPrint.push(currNode.val);
101        if (currNode.random != null) {
102            toPrintRandom.push(currNode.random.val);
103        }
104        currNode = currNode.next;
105    }
106    return toPrint.join(' -> '), toPrintRandom.join(' -> ');
107}