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Implement a stack using an array

Certification: Basic Level Accuracy: 28.57% Submissions: 7 Points: 5

Write a C# program to implement a stack data structure using an array. A stack is a linear data structure that follows the Last In First Out (LIFO) principle.

Example 1
    
  
  • Input: 
      
      
    • Push(10)
      • 
      
    • Push(20)
      • 
      
    • Push(30)
      • 
      
    • Pop()
      • 
      
    • Peek()
      • 
      
    • IsEmpty()
      • 
    
    
  
    • 
  
  • Output: 
      
      
    • 30
      • 
      
    • 20
      • 
      
    • False
      • 
    
    
  
    • 
  
  • Explanation: 
      
      
    • Step 1: Push 10, 20, and 30 to the stack to get [10, 20, 30].
      • 
      
    • Step 2: Pop() removes and returns the top element 30.
      • 
      
    • Step 3: Peek() returns the current top element 20 without removing it.
      • 
      
    • Step 4: IsEmpty() returns false as the stack still has elements.
      • 
    
    
  
    •
Example 2
    
  
  • Input: 
      
      
    • Push(5)
      • 
      
    • Pop()
      • 
      
    • Pop()
      • 
      
    • IsEmpty()
      • 
    
    
  
    • 
  
  • Output: 
      
      
    • 5
      • 
      
    • Stack Underflow
      • 
      
    • True
      • 
    
    
  
    • 
  
  • Explanation: 
      
      
    • Step 1: Push 5 to the stack to get [5].
      • 
      
    • Step 2: First Pop() removes and returns 5.
      • 
      
    • Step 3: Second Pop() tries to remove from an empty stack, resulting in "Stack Underflow".
      • 
      
    • Step 4: IsEmpty() returns true as the stack is now empty.
      • 
    
    
  
    •
Constraints
    
  
  • The capacity of the stack is fixed and determined at initialization
    • 
  
  • 0 ≤ Number of operations ≤ 1000
    • 
  
  • 0 ≤ Values pushed to the stack ≤ 10^4
    • 
  
  • Time Complexity for all operations: O(1)
    • 
  
  • Space Complexity: O(n) where n is the stack capacity
    •
ArraysStackCapgeminiSwiggy
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Hint
Solution

Solution Hints

    
  
  • Use an array to store elements and a variable to track the top index.
    • 
  
  • Implement boundary checks to avoid stack overflow and underflow.
    • 
  
  • Initialize the top index to -1 to indicate an empty stack.
    • 
  
  • Increment the top index when pushing and decrement when popping.
    • 
  
  • Return appropriate error messages or throw exceptions for invalid operations.
    •

Steps to solve by this approach:

 Step 1: Create a class with an array, a top index variable, and a capacity variable.
 Step 2: Initialize the top index to -1 to represent an empty stack.
 Step 3: Implement Push by incrementing the top index and adding the value if the stack is not full.
 Step 4: Implement Pop by returning and decrementing the top index if the stack is not empty.
 Step 5: Implement auxiliary methods like Peek, IsEmpty, and IsFull for stack operations.

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