C++ Stack Exercises: Implement a stack using a vector with push, pop operations

Last update on December 20 2024 12:32:01 (UTC/GMT +8 hours)

Write a C++ program to implement a stack using a vector with push and pop operations. Check if the stack is empty or not and find the top element of the stack.

Test Data:
Create a stack object:
Is the stack empty? Yes
Input and store (using vector) some elements onto the stack:
Stack elements are: 1 2 3 4 5
Top element is 5

Sample Solution:

C++ Code:

#include <iostream>
#include <vector>
using namespace std;

// Class representing a Stack using a vector
class Stack {
private:
    vector<int> elements; // Vector to store elements

public:
    // Function to push an element onto the stack
    void push(int element) {
        // Add element to the end of the vector
        elements.push_back(element);
    }

    // Function to pop an element from the stack
    void pop() {
        if (elements.empty()) {
            cout << "Stack is full" << endl; // Display full message if the stack is empty
        } else {
            // Remove the last element from the vector
            elements.pop_back();
        }
    }

    // Function to get the top element of the stack
    int top() {
        if (elements.empty()) {
            cout << "Stack is empty" << endl; // Display empty message if the stack is empty
            return 0;
        } else {
            // Return the last element in the vector
            return elements.back();
        }
    }

    // Function to check if the stack is empty
    bool empty() {
        // Check if the vector is empty
        return elements.empty();
    }

    // Function to display the elements of the stack
    void display() {
        vector<int> v = elements;
        if (v.empty()) {
            cout << "Stack is empty" << endl; // Display empty message if the stack is empty
            return;
        }
        cout << "Stack elements are: ";
        for (int i = 0; i < v.size(); i++) {
            cout << v[i] << " "; // Display the elements of the stack
        }
        cout << endl;
    }
};

int main() {
    Stack stack; // Create a stack object
    cout << "Create a stack object:\n";
    cout << "Is the stack empty? " << (stack.empty() ? "Yes" : "No") << endl;

    cout << "\nInput and store (using vector) some elements onto the stack:\n";
    stack.push(1);
    stack.push(2);
    stack.push(3);
    stack.push(4);
    stack.push(5);
    stack.display();
    cout << "\nTop element is " << stack.top() << endl;

    cout << "\nRemove two elements from the said stack:\n";
    stack.pop();
    stack.pop();
    stack.display();
    cout << "\nTop element is " << stack.top() << endl;

    return 0;
}

Sample Output:

Create a stack object:
Is the stack empty? Yes

Input and store (using vector) some elements onto the stack:
Stack elements are: 1 2 3 4 5

Top element is 5

Remove two elements from the said stack:
Stack elements are: 1 2 3

Top element is 3

Flowchart:

CPP Code Editor:

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Previous C++ Exercise: Middle element of a stack (using a dynamic array).
Next C++ Exercise: Sort the stack (using a vector) elements.