﻿ C++ Check the size and empty status of a stack (linked list)

# C++ Stack Exercises: Check the size and empty status of a stack (linked list)

## C++ Stack: Exercise-17 with Solution

Write a C++ program to check a stack's size and whether it is empty or not. The stack is implemented using a linked list.

Test Data:
Check a stack (using linked list) is empty or not!
Stack is empty!
Input some elements onto the stack:
Stack elements are: 0 1 3 5 6
Size of the stack is 5

Sample Solution:

C++ Code:

``````#include <iostream>

using namespace std;

// Define the node structure for the linked list
struct Node {
int data;
Node* next;
};

class Stack {
private:
// Top-of-stack pointer
Node* top;
// This variable keeps track of the stack size
int size;

public:
// Constructor to initialize an empty stack
Stack() {
top = NULL; // Initialize top pointer to NULL for an empty stack
size = 0; // Initialize the size of the stack to zero
}

// Function to push an element onto the stack
void push(int x) {
Node* new_Node = new Node(); // Create a new node
new_Node->data = x; // Assign data to the new node
new_Node->next = top; // Point the new node's next to the current top node
top = new_Node; // Update top to the new node
size++; // Increment the size of the stack
}

// Function to pop an element from the stack
void pop() {
if (top == NULL) {
cout << "Stack is empty!" << endl; // Display message if the stack is empty
return;
}
Node* temp = top; // Store the current top node
top = top->next; // Move top to the next node
size--; // Decrement the size of the stack
delete temp; // Delete the previous top node
}

// Function to display the elements of the stack
void display() {
if (top == NULL) {
cout << "Stack is empty!" << endl; // Display message if the stack is empty
return;
}
Node* temp = top; // Create a temporary node to traverse the stack
cout << "Stack elements are: ";
while (temp != NULL) {
cout << temp->data << " "; // Display the data of each node
temp = temp->next; // Move to the next node
}
cout << endl;
}

// Function to check if the stack is empty
bool isEmpty() {
return (top == NULL); // Return true if the top pointer is NULL, else false
}

// Function to find the size of the stack
int getSize() {
return size; // Return the size of the stack
}
};

int main() {
Stack stk; // Create an object of Stack class
cout << "Check a stack (using linked list) is empty or not!\n";
stk.display(); // Display the stack status
cout << "\nInput some elements onto the stack:\n";
stk.push(6);
stk.push(5);
stk.push(3);
stk.push(1);
stk.push(0);
stk.display(); // Display the elements in the stack
cout << "\nSize of the stack is " << stk.getSize() << endl; // Display the size of the stack
cout << "\nRemove two elements from the said stack:\n";
stk.pop();
stk.pop();
stk.display(); // Display the updated stack
cout << "Size of the stack is " << stk.getSize() << endl; // Display the size of the stack
return 0;
}
``````

Sample Output:

```Check a stack (using linked list) is empty or not!
Stack is empty!

Input some elements onto the stack:
Stack elements are: 0 1 3 5 6

Size of the stack is 5

Remove two elements form the said stack:
Stack elements are: 3 5 6
Size of the stack is 3
```

Flowchart:

CPP Code Editor: