1. CS148 Introduction to Programming II
Ayman Abdel-Hamid
Department of Computer Science
Old Dominion University
Lecture 12: 2/24/2003
Lecture 12: 2/24/2003
CS148 Spring 2003

2. Outline Linked lists Operations on linked lists Insert at back
Insert at front
Lecture 12: 2/24/2003
CS148 Spring 2003

3. Linked Lists
A list represented as an array is a sequential structure (successive components of the array are located next to each other in memory
Efficient for searching in a sorted list using a binary search
Insertion/deletion in a sorted array?
A linked list is a collection of nodes.
Nodes are scattered in memory, not in consecutive memory locations
Each node is represented by a struct consisting of two main components
Data Component (one or more struct members)
Link Component (gives location of next node in the list)
Lecture 12: 2/24/2003
CS148 Spring 2003

4. Linked Lists struct node { int ID; //Node ID string name;
Data
Component
Link
A node in a linked list
struct node {
int ID; //Node ID
string name;
node* next; //pointer to next node };
HEAD 1 2
(N-1) N
points to NULL
(the end of the list)
A linked list (HEAD gives the location of the first node in the list)
Lecture 12: 2/24/2003
CS148 Spring 2003

5. Insertion at back of listp
HEAD
NewNode
struct node {
int ID; //Node ID
string name;
node* next; //pointer to next node };
node *p,*NewNode;
//allocate new node and fill
NewNode = new node;
NewNode->next = NULL;
//link NewNode to the node pointed to by p
p->next = NewNode;
NewNode p
Lecture 12: 2/24/2003
CS148 Spring 2003

6. Insertion at front of list
NewNode
HEAD
struct node {
int ID; //Node ID
string name;
node* next; //pointer to next node };
HEAD
NewNode
node *p,*NewNode;
//allocate new node
NewNode = new node;
//make NewNode the first node in the list
NewNode->next = HEAD;
HEAD = NewNode;
HEAD
NewNode
Lecture 12: 2/24/2003
CS148 Spring 2003