Stack_in_cpp

Theory

A stack is a linear data structure that follows the LIFO (Last In, First Out) principle.

This means that the last element inserted into the stack is the first one to be removed.

In a stack, all insertions and deletions happen at one end, called the top. There is also a pointer, often called the top pointer, which keeps track of the current topmost element.

If an attempt is made to push an element into a full stack, it results in stack overflow, whereas trying to pop an element from an empty stack results in stack underflow.

Stacks are essential in many real-world applications such as function call management in programming languages (call stack), undo/redo operations in text editors, expression evaluation in compilers, and backtracking algorithms. By organizing data in this manner, stacks provide a controlled and efficient way to manage temporary data, ensuring that operations are performed in a structured sequence.

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Key Operations

Push

• Inserts an element into the stack at the top.
• If the stack is already full (maximum capacity), stack overflow occurs.

Pop

• Removes the topmost element from the stack.
• If the stack is empty, stack underflow occurs.

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Characteristics of Stack

• Linear Data Structure: Elements are arranged sequentially.
• LIFO Principle: Most recently added element is removed first.
• Top Pointer: Keeps track of the current topmost element.
• Fixed Size: When using arrays, the stack has a maximum capacity.

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Applications of Stack

• Function Call Management: The call stack manages function calls and returns.
• Expression Evaluation: Conversion and evaluation of infix, postfix, and prefix expressions.
• Undo/Redo Operations: Text editors and graphics software use stacks to store previous states.
• Memory Management: Stack memory stores local variables and function call information.
• Backtracking Algorithms: Maze solving, recursion, and parsing algorithms.

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Algorithm

Push Operation

1. Start.
2. Check if the stack is full (top >= MAX - 1):
   • If yes, display "Stack Overflow" and stop.
3. Increment top by 1.
4. Insert the new element at arr[top].
5. Display a message indicating the element is pushed successfully.
6. Stop.

Pop Operation

1. Start.
2. Check if the stack is empty (top < 0):
   • If yes, display "Stack Underflow" and stop.
3. Display the element at arr[top] being removed.
4. Decrement top by 1.
5. Stop.

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Conclusion

The experiment successfully demonstrates the stack data structure and its LIFO behavior.

• The push operation adds elements to the top of the stack, while the pop operation removes the topmost element.
• Overflow and underflow conditions were properly handled, emphasizing the importance of boundary checks.
• Stacks are fundamental in programming and applications such as function call management, expression evaluation, memory management, and algorithm design.
• Using arrays, stacks can be efficiently implemented with a fixed-size memory allocation, suitable for scenarios where the maximum number of elements is known.