Cracking the Coding Interview, 4 Edition - 150 Programming Interview Questions and Solutions

Chapter 2 | Linked Lists
How to Approach:
Linked list questions are extremely common. These can range from simple (delete a node in
a linked list) to much more challenging. Either way, we advise you to be extremely comfortable
with the easiest questions. Being able to easily manipulate a linked list in the simplest
ways will make the tougher linked list questions much less tricky. With that said, we present
some “must know” code about linked list manipulation. You should be able to easily write
this code yourself prior to your interview.
Creating a Linked List:
NOTE: When you’re discussing a linked list in an interview, make sure to understand
whether it is a single linked list or a doubly linked list.
1 class Node {
2 Node next = null;
3 int data;
4 public Node(int d) { data = d; }
5 void appendToTail(int d) {
6 Node end = new Node(d);
7 Node n = this;
8 while (n.next != null) { n = n.next; }
9 n.next = end;
10 }
11 }
Deleting a Node from a Singly Linked List
1 Node deleteNode(Node head, int d) {
2 Node n = head;
3 if (n.data == d) {
4 return head.next; /* moved head */
5 }
6 while (n.next != null) {
7 if (n.next.data == d) {
8 n.next = n.next.next;
9 return head; /* head didn’t change */
10 }
11 n = n.next;
12 }
13 }
4 9
Cracking the Coding Interview | Data Structures