﻿ C# - Sort the elements of a stack in descending order

# C#: Sort the elements of a stack in descending order

## C# Sharp Stack: Exercise-2 with Solution

Write a C# program to sort the elements of a given stack in descending order.

Sample Solution:

C# Code:

``````using System;
// Implementation of a Stack data structure
public class Stack
{
private int[] items; // Array to hold stack elements
private int top;     // Index representing the top of the stack
// Constructor to initialize the stack with a specified size
public Stack(int size)
{
items = new int[size]; // Initializing the array with the given size
top = -1;              // Initializing top to -1, indicating an empty stack
}
// Method to check if the stack is empty
public bool IsEmpty()
{
return top == -1; // Returns true if top is -1 (empty stack), otherwise false
}
// Method to check if the stack is full
public bool IsFull()
{
return top == items.Length - 1; // Returns true if top is at the last index of the array (full stack)
}
// Method to push an element onto the stack
public void Push(int item)
{
if (IsFull())
{
Console.WriteLine("Stack Full!"); // Displays a message if the stack is full
return;
}
items[++top] = item; // Inserts the item at the incremented top index
}
// Method to pop an element from the stack
public int Pop()
{
if (IsEmpty())
{
Console.WriteLine("Stack underflow"); // Displays a message if the stack is empty
return -1;
}
return items[top--]; // Removes and returns the top element by decrementing top
}
// Method to peek at the top element of the stack without removing it
public int Peek()
{
if (IsEmpty())
{
Console.WriteLine("Stack is empty"); // Displays a message if the stack is empty
return -1;
}
return items[top]; // Returns the element at the top index without removing it
}
// Method to get the current size of the stack
public static int Size(Stack stack)
{
return stack.top + 1; // Returns the number of elements in the stack
}
// Method to sort the stack elements in descending order
public static void SortDescending(Stack stack)
{
if (stack.IsEmpty())
{
Console.WriteLine("Stack is empty");
return;
}
// Creating a temporary stack to hold sorted elements
Stack tempStack = new Stack(stack.items.Length);
// Sorting elements in descending order
while (!stack.IsEmpty())
{
int currentItem = stack.Pop();
while (!tempStack.IsEmpty() && currentItem > tempStack.Peek())
{
stack.Push(tempStack.Pop());
}
tempStack.Push(currentItem);
}
while (!tempStack.IsEmpty())
{
stack.Push(tempStack.Pop());
}
}

// Method to display the stack elements
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] + " "); // Displays each element in the stack
}
}
}
// Main class to demonstrate the functionality of the Stack class
public class Program
{
public static void Main(string[] args)
{
Console.WriteLine("Initialize a stack:");
Stack stack = new Stack(10); // Creating a stack with a size of 10
Console.WriteLine("\nInput some elements onto the stack:");
stack.Push(1);
stack.Push(3);
stack.Push(3);
stack.Push(9);
stack.Push(5);
Stack.Display(stack); // Displaying the elements in the stack
Stack.SortDescending(stack); // Sorting stack elements in descending order
Console.WriteLine("\nStack elements in descending order:");
Stack.Display(stack); // Displaying the sorted elements
Console.WriteLine("\nInput two more elements onto the stack:");
stack.Push(0);
stack.Push(10);
Stack.Display(stack);
Console.WriteLine("\nStack elements in descending order:");
Stack.SortDescending(stack); // Sorting stack elements again in descending order
Stack.Display(stack); // Displaying the sorted elements
}
}
``````

Sample Output:

```Initialize a stack:

Input some elements onto the stack:
Stack elements:
5 9 3 3 1
Stack elements in descending order:
Stack elements:
9 5 3 3 1
Input two more elements onto the stack:
Stack elements:
10 0 9 5 3 3 1
Stack elements in descending order:
Stack elements:
10 9 5 3 3 1 0
```

Flowchart:

C# Sharp Code Editor:

Improve this sample solution and post your code through Disqus

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

﻿