Stack Implementation Using Linked List in DSA C - Build from Scratch

Stack Implementation Using Linked List

📖 Scenario: Imagine you are building a simple program to manage a stack of books. You want to add and remove books in a last-in, first-out order. To do this efficiently, you will use a linked list to implement the stack.

🎯 Goal: Build a stack using a linked list in C. You will create the linked list nodes, add a configuration variable for the stack top, implement push and pop operations, and finally print the stack contents.

📋 What You'll Learn

Define a struct for the linked list node with an integer data and a pointer to the next node

Create a pointer variable called top to track the top of the stack

Implement a push function to add an element to the stack

Implement a pop function to remove the top element from the stack

Print the stack elements from top to bottom

💡 Why This Matters

🌍 Real World

Stacks are used in many real-world applications like undo features in text editors, browser history, and expression evaluation.

💼 Career

Understanding stack implementation helps in software development roles that require knowledge of data structures and memory management.

1

Define the Node Structure

Define a struct called Node with an integer data and a pointer next to another Node.

DSA C

// Define the Node struct
// Your code here

Hint

Use typedef struct Node to define the node. It should have int data and struct Node* next.

2

Create the Stack Top Pointer

Create a pointer variable called top of type Node* and initialize it to NULL.

DSA C

#include 
#include 

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

// Create the top pointer for the stack
// Your code here

Hint

Declare Node* top = NULL; to mark the stack as empty initially.

3

Implement Push and Pop Functions

Write a function void push(int value) that creates a new Node with data = value, sets its next to top, and updates top to this new node. Also write a function int pop() that removes the top node, returns its data, and updates top to the next node. If the stack is empty, return -1.

DSA C

#include 
#include 

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

Node* top = NULL;

// Implement push and pop functions
// Your code here

Hint

In push, create a new node, set its data and next, then update top. In pop, check if top is NULL, else remove the top node and return its data.

4

Print Stack Contents

Write a function void printStack() that prints the stack elements from top to bottom separated by -> and ending with NULL. Then push the values 10, 20, and 30 onto the stack and call printStack().

DSA C

#include 
#include 

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

Node* top = NULL;

void push(int value) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = value;
    newNode->next = top;
    top = newNode;
}

int pop() {
    if (top == NULL) {
        return -1;
    }
    int value = top->data;
    Node* temp = top;
    top = top->next;
    free(temp);
    return value;
}

// Write printStack function and push 10, 20, 30, then print
// Your code here

Hint

Traverse from top to NULL, printing each data followed by ->. After pushing 10, 20, 30, the print should show 30 -> 20 -> 10 -> NULL.