Linked Lists in Data Structures

Linked Lists

• A data structure in which a sequence of nodes are linked together through pointers
• Each node contains a value and a reference (i.e., a "link") to the next node in the sequence
• Advantages:
  • Dynamic memory allocation: nodes can be added or removed as needed
  • Efficient insertion and deletion operations
• Disadvantages:
  • Slow search time (O(n) in the worst case)
  • More complex implementation compared to arrays
• Types of linked lists:
  • Singly linked list: each node only has a reference to the next node
  • Doubly linked list: each node has references to both the previous and next nodes
  • Circularly linked list: the last node points back to the first node

Queues

• A First-In-First-Out (FIFO) data structure
• Elements are added to the end of the queue (enqueue) and removed from the front of the queue (dequeue)
• Operations:
  • Enqueue: add an element to the end of the queue
  • Dequeue: remove the element from the front of the queue
  • Peek: look at the element at the front of the queue without removing it
• Types of queues:
  • Linear queue: a simple queue with a fixed maximum size
  • Circular queue: a queue that wraps around to the beginning when the end is reached
  • Priority queue: elements are ordered based on their priority, with the highest-priority element at the front

Linked Lists

• A linked list is a dynamic data structure where a sequence of nodes are linked together through pointers.
• Each node in a linked list contains a value and a reference (or "link") to the next node in the sequence.
• Linked lists have advantages, including:
  • Dynamic memory allocation, allowing nodes to be added or removed as needed.
  • Efficient insertion and deletion operations.
• However, linked lists also have disadvantages, including:
  • Slow search time, with a worst-case time complexity of O(n).
  • More complex implementation compared to arrays.
• There are several types of linked lists, including:
  • Singly linked lists, where each node only has a reference to the next node.
  • Doubly linked lists, where each node has references to both the previous and next nodes.
  • Circularly linked lists, where the last node points back to the first node.

Queues

• A queue is a First-In-First-Out (FIFO) data structure.
• Elements are added to the end of the queue (enqueue) and removed from the front of the queue (dequeue).
• Queue operations include:
  • Enqueue: adding an element to the end of the queue.
  • Dequeue: removing the element from the front of the queue.
  • Peek: looking at the element at the front of the queue without removing it.
• There are several types of queues, including:
  • Linear queues, which are simple queues with a fixed maximum size.
  • Circular queues, which wrap around to the beginning when the end is reached.
  • Priority queues, where elements are ordered based on their priority, with the highest-priority element at the front.