C++ Reverse the stack (using a Deque) elements

Last update on December 20 2024 12:25:43 (UTC/GMT +8 hours)

Write a C++ program that reverse the stack (using a Deque) elements.

Test Data:
Create a stack object:
Input and store (using Deque) some elements onto the stack:
Stack elements are: 1 3 2 6 5 -1 0
Reverse the stack items in ascending order:
Stack elements are: 0 -1 5 6 2 3 1

Sample Solution:

C++ Code:

#include <iostream>
#include <deque>
#include <algorithm>

using namespace std;

class Stack {
private:
    deque<int> elements; // Deque to store elements

public:
    // Function to add an element to the stack
    void push(int element) {
        elements.push_back(element); // Add element to deque
    }

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

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

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

    // Function to reverse elements in the stack
    void reverse_elements() {
        if (elements.empty()) {
            cout << "Stack is empty" << endl; // Display empty message if deque is empty
            return;
        }
        reverse(elements.begin(), elements.end()); // Reverse elements 
    }

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

int main() {
    Stack stack;
    //Initialize a stack 
    cout << "Create a stack object:\n";
    cout << "\nInput and store (using Deque) some elements onto the stack:\n";
    stack.push(1);
    stack.push(3);
    stack.push(2);
    stack.push(6);
    stack.push(5);
    stack.push(-1);
    stack.push(0);
    stack.display();
    cout << "\nReverse the stack items:\n";
    stack.reverse_elements();
    stack.display();
    cout << "\nRemove two elements from the stack:\n";
    stack.pop();
    stack.pop();
    stack.display();
    cout << "\nInput three elements onto the stack:\n";
    stack.push(4);
    stack.push(7);
    stack.push(-2);
    stack.display();
    cout << "\nReverse the said items:\n";
    stack.reverse_elements();
    stack.display();
    return 0;
}

Sample Output:

Create a stack object:

Input and store (using Deque) some elements onto the stack:
Stack elements are: 1 3 2 6 5 -1 0 

Reverse the stack items:
Stack elements are: 0 -1 5 6 2 3 1 

Remove two elements from the stack:
Stack elements are: 0 -1 5 6 2 

Input three elements onto the stack:
Stack elements are: 0 -1 5 6 2 4 7 -2 

Reverse the said items:
Stack elements are: -2 7 4 2 6 5 -1 0 

Flowchart:

CPP Code Editor:

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Previous C++ Exercise: Sort the stack (using a Deque) elements.