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Stack - Linked List Implementation

Last Updated : 01 Aug, 2025

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To implement a stack using a singly linked list, we follow the LIFO (Last In, First Out) principle by inserting and removing elements from the head of the list, where each node stores data and a pointer to the next node.

In the stack Implementation, a stack contains a top pointer. which is the "head" of the stack where pushing and popping items happens at the head of the list. The first node has a null in the link field and second node-link has the first node address in the link field and so on and the last node address is in the "top" pointer.

The main advantage of using a linked list over arrays is that it is possible to implement a stack that can shrink or grow as much as needed.
Using an array will put a restriction on the maximum capacity of the array which can lead to stack overflow. Here each new node will be dynamically allocated. so overflow is not possible.
If we use built in dynamic sized arrays like vector in C++, list in Python or ArrayList in Java, we get automatically growing stack, but the worst case time complexity is not O(1) for push() and pop() as there might be a resizing step once in a while. With Linked List, we get worst case O(1).

Stack Operations

push(): Insert a new element into the stack (i.e just insert a new element at the beginning of the linked list.)
pop(): Return the top element of the Stack (i.e simply delete the first element from the linked list.)
peek(): Return the top element.
display(): Print all elements in Stack.

Push Operation

Initialise a node

Update the value of that node by data i.e. node->data = data

Now link this node to the top of the linked list

And update top pointer to the current node

Pop Operation

First Check whether there is any node present in the linked list or not, if not then return

Otherwise make pointer let say temp to the top node and move forward the top node by 1 step

Now free this temp node

Peek Operation

Check if there is any node present or not, if not then return.

Otherwise return the value of top node of the linked list

Display Operation

Take a temp node and initialize it with top pointer

Now start traversing temp till it encounters NULL

Simultaneously print the value of the temp node

C++


 #include <bits/stdc++.h>
using namespace std;

// Node structure
class Node {
public:
    int data;
    Node* next;
    Node(int new_data) {
        this->data = new_data;
        this->next = nullptr;
    }
};

// Stack using linked list
class Stack {
    Node* head;

public:
    Stack() {
        this->head = nullptr;
    }

    // Check if stack is empty
    bool isEmpty() {
        return head == nullptr;
    }

    // Push an element onto stack
    void push(int new_data) {
        Node* new_node = new Node(new_data);
        new_node->next = head;
        head = new_node;
    }

    // Pop the top element
    void pop() {
        if (isEmpty()) return;
        Node* temp = head;
        head = head->next;
        delete temp;
    }

    // Return the top element
    int peek() {
        if (!isEmpty()) return head->data;
        return INT_MIN;
    }
};

int main() {
    Stack st;

    st.push(11);
    st.push(22);
    st.push(33);
    st.push(44);

    cout << st.peek() << endl;

    st.pop();
    st.pop();

    cout << st.peek() << endl;

    return 0;
}


 #include <stdio.h>
#include <stdlib.h>
#include <limits.h>

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

// Check if stack is empty
int isEmpty(struct Node* head) {
    return head == NULL;
}

// Push an element onto stack
void push(struct Node** head, int new_data) {
    struct Node* new_node = (struct Node*)malloc(sizeof(struct Node));
    new_node->data = new_data;
    new_node->next = *head;
    *head = new_node;
}

// Pop the top element
void pop(struct Node** head) {
    if (isEmpty(*head)) return;
    struct Node* temp = *head;
    *head = (*head)->next;
    free(temp);
}

// Return the top element
int peek(struct Node* head) {
    if (!isEmpty(head)) return head->data;
    return INT_MIN;
}

int main() {
    struct Node* head = NULL;

    push(&head, 11);
    push(&head, 22);
    push(&head, 33);
    push(&head, 44);

    printf("%d\n", peek(head));

    pop(&head);
    pop(&head);

    printf("%d\n", peek(head));

    return 0;
}

Java


 class Node {
    int data;
    Node next;

    Node(int new_data) {
        this.data = new_data;
        this.next = null;
    }
}

// Stack using linked list
class Stack {
    Node head;

    Stack() {
        this.head = null;
    }

    // Check if stack is empty
    boolean isEmpty() {
        return head == null;
    }

    // Push an element onto stack
    void push(int new_data) {
        Node new_node = new Node(new_data);
        new_node.next = head;
        head = new_node;
    }

    // Pop the top element
    void pop() {
        if (isEmpty()) return;
        head = head.next;
    }

    // Return the top element
    int peek() {
        if (!isEmpty()) return head.data;
        return Integer.MIN_VALUE;
    }
}

public class Main {
    public static void main(String[] args) {
        Stack st = new Stack();

        st.push(11);
        st.push(22);
        st.push(33);
        st.push(44);

        System.out.println(st.peek());

        st.pop();
        st.pop();

        System.out.println(st.peek());
    }
}

Python


 # Node structure
class Node:
    def __init__(self, new_data):
        self.data = new_data
        self.next = None

# Stack using linked list
class Stack:
    def __init__(self):
        self.head = None

    # Check if stack is empty
    def isEmpty(self):
        return self.head is None

    # Push an element onto stack
    def push(self, new_data):
        new_node = Node(new_data)
        new_node.next = self.head
        self.head = new_node

    # Pop the top element
    def pop(self):
        if self.isEmpty():
            return
        self.head = self.head.next

    # Return the top element
    def peek(self):
        if not self.isEmpty():
            return self.head.data
        return float('-inf')

st = Stack()

st.push(11)
st.push(22)
st.push(33)
st.push(44)

print(st.peek())

st.pop()
st.pop()

print(st.peek())


 using System;

// Node structure
class Node {
    public int data;
    public Node next;

    public Node(int new_data) {
        this.data = new_data;
        this.next = null;
    }
}

// Stack using linked list
class Stack {
    Node head;

    public Stack() {
        this.head = null;
    }

    // Check if stack is empty
    public bool isEmpty() {
        return head == null;
    }

    // Push an element onto stack
    public void push(int new_data) {
        Node new_node = new Node(new_data);
        new_node.next = head;
        head = new_node;
    }

    // Pop the top element
    public void pop() {
        if (isEmpty()) return;
        head = head.next;
    }

    // Return the top element
    public int peek() {
        if (!isEmpty()) return head.data;
        return int.MinValue;
    }
}

class Program {
    static void Main() {
        Stack st = new Stack();

        st.push(11);
        st.push(22);
        st.push(33);
        st.push(44);

        Console.WriteLine(st.peek());

        st.pop();
        st.pop();

        Console.WriteLine(st.peek());
    }
}

JavaScript


 // Node structure
class Node {
    constructor(new_data) {
        this.data = new_data;
        this.next = null;
    }
}

// Stack using linked list
class Stack {
    constructor() {
        this.head = null;
    }

    // Check if stack is empty
    isEmpty() {
        return this.head === null;
    }

    // Push an element onto stack
    push(new_data) {
        let new_node = new Node(new_data);
        new_node.next = this.head;
        this.head = new_node;
    }

    // Pop the top element
    pop() {
        if (this.isEmpty()) return;
        this.head = this.head.next;
    }

    // Return the top element
    peek() {
        if (!this.isEmpty()) return this.head.data;
        return Number.MIN_SAFE_INTEGER;
    }
}

let st = new Stack();

st.push(11);
st.push(22);
st.push(33);
st.push(44);

console.log(st.peek());

st.pop();
st.pop();

console.log(st.peek());

Time Complexity: O(1), for all push(), pop(), and peek(), as we are not performing any kind of traversal over the list.
Auxiliary Space: O(n), where n is the size of the stack

Benefits of implementing a stack using a singly linked list

Dynamic memory allocation: The size of the stack can be increased or decreased dynamically by adding or removing nodes from the linked list, without the need to allocate a fixed amount of memory for the stack upfront.
Efficient memory usage: Since nodes in a singly linked list only have a next pointer and not a prev pointer, they use less memory than nodes in a doubly linked list.
Easy implementation: Implementing a stack using a singly linked list is straightforward and can be done using just a few lines of code.
Versatile: Singly linked lists can be used to implement other data structures such as queues, linked lists, and trees.

Real time examples of stack

Stacks are used in various real-world scenarios where a last-in, first-out (LIFO) data structure is required. Here are some examples of real-time applications of stacks:

Function Call Stack: When a function is called, its return address and parameters are pushed onto the stack. The stack ensures functions execute and return in reverse order..
Undo/Redo Operations: In apps like text or image editors, actions are pushed onto a stack. Undo removes the last action, while redo restores it.
Browser History: Browsers use stacks to track visited pages. Visiting a page pushes its URL onto the stack, and the "Back" button pops the last URL to go to the previous page.
Expression Evaluation: In compilers, expressions are converted to postfix notation and evaluated using a stack.
Call Stack in Recursion: Recursive function calls are pushed onto the stack. Once recursion ends, the stack is popped to return to the previous function call.

Linked List Implementation of Stack in C++ Linked List Implementation of Stack in Java Linked List Implementation of Stack in Python

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