Stacks

A stack is a structure where the last element that enters is the first one that leaves.

That’s known as LIFO: Last In, First Out.

In this lesson you will learn:

• what a stack is
• traversal in stacks
• search in stacks
• insertion in stacks
• basic extraction

Insertion: push

Adding an element to the stack is known as push.

Extraction: pop

Removing the top element is known as pop.

Traversal

Traversal visits elements from the top downward.

Search

Search is done by traversing the stack element by element.

Node example

struct Node {
    int data;
    struct Node* next;
};

Summary

• a stack follows the LIFO rule
• inserting is called push
• extracting is called pop
• it can also be traversed and searched

Final idea

The stack is excellent for understanding that not all structures allow accessing data in any way. Each has its own logic of use.