This document discusses arrays and linked lists as data structures. It outlines the pros and cons of arrays, which have fixed size and allow constant time access but require contiguous memory. Linked lists are introduced as a solution, using dynamic memory allocation so nodes can be anywhere in memory. Each linked list node stores data and a link to the next node. Linked lists provide flexibility for insertion and deletion at any position in constant time but are more complex to use than arrays.

1. CS250 - Data Structures and
Algorithm
BESE-2A/B
Lecture 03

2. •
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Outline
Problem with arrays
Solution
Introduction to Linked List
Arrays vs. Linked List
Linked List Pros & Cons
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3. Our Prime Concern
• Performance & Efficiency
– In terms of time ;
• faster the execution, better the algorithm
– In terms of space ;
• lesser the space, better the data structure
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4. Pros
• Easier to use and access
• Faster access to the
elements
– Takes constant time
– Base + ( item_number *
number_of_bytes)
Cons
• Fixed size
• One block allocation
– Fails if enough contiguous
memory isn’t available
• Complex position based
insertion
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– Expensive to maintain
ordered data OR insertion at
beginning
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Arrays
Most common data structure to implement
collections or to store data

5. Arrays
• Solution
– Dynamic Memory Allocation
– Faster insertion and deletion of elements without
changing the existing items
• Linked List
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6. Linked List
• Linked structure is a collection of
nodes storing data and links to
other nodes
• Dynamic Memory Allocation
– Consequently, nodes can locate
anywhere in the memory and each
node can point to any other node
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7. Linked List
• Linked structure is a collection of nodes storing
data and link to other nodes
struct Node {
int data;
Node * next;
};
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8. Array vs. Linked List
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9. Linked List
Pros
• Dynamic allocation
– the size is not required to be
known in advance
• Flexibility
– insert at (or delete from) any
position in constant time
• No single allocation of
memory needed
Cons
• Complex to use and access
– relatively complex as
compared to arrays
• No constant time access to
the elements
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10. Question?
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