reading-notes

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Stacks and Queues 📁

What is a Stack ❓

• A stack is a data structure that consists of *Nodes*, Each *Node* references the next Node in the stack.

• Terminology for a stack is :

  • Push , put into the stack are pushed
  • Pop , removed from the stack are popped
  • Top , top of the stack
  • Peek , view the value of the top Node,
  • IsEmpty , returns true when stack is empty otherwise returns false.

    will always be an O(1)

• Stacks concepts:

  • FILO (First In Last Out)

  • LIFO (Last In First Out)

• Stack Visualization

What is a Queue ❓

• A Queue is a linear structure that follows a particular order in which the operations are performed. The order is First In First Out (FIFO).

  An example: any queue of consumers for a resource where the consumer that came first is served first. The difference between stacks and queues is in removing.

📁

• Terminology for a queue:

  • Enqueue (added)
  • Dequeue (removed)
  • Front (first Node)
  • Rear (last Node)
  • Peek (view the value of the front Node)
  • IsEmpty ( returns true when queue is empty otherwise returns false.)

    will always be an O(1)

• Queues concepts:

  • FILO (First In Last Out)
  • LILO (Last In Last Out)

• Queue Visualization