C#: Checks if two stacks are equal

Last update on December 20 2024 12:43:47 (UTC/GMT +8 hours)

Write a C# program that implements a stack and checks if two stacks are equal.

Sample Solution:

C# Code:

using System;
using System.Collections;
using System.Collections.Generic;

public class Stack
{
    private int[] items; // Array to hold stack elements
    private int top; // Index indicating the top of the stack

    // Constructor to initialize the stack with a specified size
    public Stack(int size)
    {
        items = new int[size]; // Creating an array of integers with the given size
        top = -1; // Initializing top index to -1 indicating an empty stack
    }

    // Check if the stack is empty
    public bool IsEmpty()
    {
        return top == -1; // Stack is empty if top is -1
    }

    // Check if the stack is full
    public bool IsFull()
    {
        return top == items.Length - 1; // Stack is full if top equals the last index of the array
    }

    // Push an element onto the stack
    public void Push(int item)
    {
        if (IsFull()) // Check if the stack is full
        {
            Console.WriteLine("Stack Full!"); // Display a message indicating stack overflow
            return;
        }

        items[++top] = item; // Increment top and add the item to the stack
    }

    // Pop an element from the stack
    public int Pop()
    {
        if (IsEmpty()) // Check if the stack is empty
        {
            Console.WriteLine("Stack underflow"); // Display a message indicating stack underflow
            return -1;
        }

        return items[top--]; // Return and decrement top to remove the element from the stack
    }

    // Peek at the top element of the stack without removing it
    public int Peek()
    {
        if (IsEmpty()) // Check if the stack is empty
        {
            Console.WriteLine("Stack is empty"); // Display a message indicating the stack is empty
            return -1;
        }

        return items[top]; // Return the top element of the stack
    }

    // Static method to get the size of a stack
    public static int Size(Stack stack)
    {
        return stack.top + 1; // Return the size of the stack based on the current top index
    }

    // Method to count all the elements in a stack
    public static int Count(Stack stack)
    {
        int count = 0; // Initialize count variable to track the number of elements

        Stack temp = new Stack(Size(stack)); // Create a temporary stack to preserve the original stack order

        // Move elements from the original stack to the temporary stack and count them
        while (!stack.IsEmpty())
        {
            temp.Push(stack.Pop()); // Move elements from original stack to temporary stack
            count++; // Increment count for each element moved
        }

        // Restore the original stack by moving elements back from the temporary stack
        while (!temp.IsEmpty())
        {
            stack.Push(temp.Pop()); // Move elements back to the original stack
        }

        return count; // Return the total count of elements in the stack
    }

    // Static method to clear the stack by popping all elements
    public static void Clear(Stack stack)
    {
        while (!stack.IsEmpty())
        {
            stack.Pop(); // Remove elements from the stack until it's empty
        }
    }

    // Method to check if an element is present or not in a stack
    public static bool Contains(Stack stack, int item)
    {
        if (stack == null || stack.IsEmpty())
            return false;

        bool found = false;
        Stack tempStack = new Stack(Size(stack));

        while (!stack.IsEmpty())
        {
            int current = stack.Pop();
            if (current == item)
            {
                found = true;
                break;
            }
            tempStack.Push(current);
        }

        while (!tempStack.IsEmpty())
        {
            stack.Push(tempStack.Pop());
        }

        return found;
    }

    // Check if two stacks are equal or not
    public static bool AreStacksEqual(Stack stack1, Stack stack2)
    {
        if (stack1 == null || stack2 == null)
        {
            return false;
        }

        if (Count(stack1) != Count(stack2))
        {
            return false;
        }

        Stack temp1 = new Stack(Count(stack1));
        Stack temp2 = new Stack(Count(stack2));

        while (Count(temp1) > 0 && Count(temp2) > 0)
        {
            if (!temp1.Pop().Equals(temp2.Pop()))
            {
                return false;
            }
        }

        return true;
    }

    // Method to display the elements of the stack
    public static void Display(Stack stack)
    {
        if (stack.IsEmpty())
        {
            Console.WriteLine("Stack is empty");
            return;
        }

        Console.WriteLine("Stack elements:");
        for (int i = stack.top; i >= 0; i--)
        {
            Console.Write(stack.items[i] + " ");
        }
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        Console.WriteLine("Initialize a stack:");
        Stack stack1 = new Stack(6);
        stack1.Push(1);
        stack1.Push(2);
        stack1.Push(3);
        stack1.Push(4);
        stack1.Push(5);
        stack1.Push(6);
        Console.WriteLine("\nStack-1");
        Stack.Display(stack1);
        Stack stack2 = new Stack(3);
        stack2.Push(1);
        stack2.Push(2);
        stack2.Push(3);
        Console.WriteLine("\nStack-2");
        Stack.Display(stack2);
        Stack stack3 = new Stack(3);
        stack3.Push(1);
        stack3.Push(2);
        stack3.Push(3);
        Console.WriteLine("\nStack-3");
        Stack.Display(stack3);
        Console.WriteLine("\nIf stack2 is equal of stack3!");
        bool result = Stack.AreStacksEqual(stack2, stack3);
        Console.WriteLine("{0}", result);
        Console.WriteLine("\nIf stack1 is equal of stack3!");
        result = Stack.AreStacksEqual(stack1, stack3);
        Console.WriteLine("{0}", result);
        Console.WriteLine("\nIf stack1 is equal of stack2!");
        result = Stack.AreStacksEqual(stack1, stack2);
        Console.WriteLine("{0}", result);
    }
}

Sample Output:

Initialize a stack:

Stack-1
Stack elements:
6 5 4 3 2 1
Stack-2
Stack elements:
3 2 1
Stack-3
Stack elements:
3 2 1
If stack2 is equal of stack3!
True

If stack1 is equal of stack3!
False

If stack1 is equal of stack2!
False

Flowchart:

C# Sharp Code Editor:

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