Unit 3: Stacks and Queues

3.1 Stack

Stack is a linear data structure which follows a particular order in which the operations are performed. The order may be LIFO(Last In First Out) or FILO(First In Last Out).

Key Operations

• Push: Adds an item in the stack. If the stack is full, then it is said to be an Overflow condition.
• Pop: Removes an item from the stack. The items are popped in the reversed order in which they are pushed. If the stack is empty, then it is said to be an Underflow condition.
• Peek or Top: Returns top element of stack.

3.2 Queue

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