Stack and it’s Basic Operations

A stack is a linear data structure in which operations are done in a specific order, as defined by the data structure. The sequence may be LIFO (Last in, first-out) or FILO (First in, last out) (First In, Last Out). A stack can be found in a variety of real-world situations. Let’s take the simple case of plates stacked on top of one another in a canteen as an illustration. The plate that is at the top of the stack is the first one to be removed, whereas the plate that is at the bottom of the stack is the one that remains in the stack for the longest period of time, as seen in the diagram. As a result, it is easy to observe that it follows the LIFO/FILO sequence.

Applications of Stack Data Structure

• Text editors with an “undo” feature, web browsers with a forward and backward feature, and other features are available
• The evaluation of expressions and the parsing of syntax are two of the most important components of a programming language’s capability
• Backtracking. In a sequence of data elements, this is the process to follow if you need to get the most recent data element from the sequence. Consider the following scenario: you’re in a maze; how do you find your way from one entrance to the next? Once you’ve reached a dead end, there’s nothing you can do but go backwards. But where exactly do you want to go back to? Returning to the previous selection point, you have created a stack that contains all of the potential possibilities available at each selection point. Then selecting a different choice from the selection stack is all that is required to go back in time
• Stacks are used to implementing iterative implementations of numerous recursive programmes, such as tree traversals, DFS traversals in a graph, and other similar operations
• An algorithm’s information is organised using a stack, which is a primary data structure in the field of algorithms. Stacks are used to addressing a range of problems in the field of algorithms
• Memory management is the process of organising and storing information. In any modern computer environment, a stack is the underlying memory management architecture that allows a programme to operate efficiently
• Stacks can be used to examine whether or not the parenthesis of an expression matches. Stacks can be used to convert from one type of expression to another kind of expression. Memory management can be accomplished through the usage of stacks. Backtracking problems are solved with the use of stack data structures

Types of Operation

Push: Insert an element onto the top of the stack

The operation of pushing an element into the stack is referred to as a push operation in this context. Given that there is only one conceivable location in which the new element can be inserted — at the top of the stack — the new element is automatically positioned at the top of the stack.

Pop: Delete the topmost element and return it

Taking an element out of the picture is referred to as a pop operation. The fact that we can only remove one element from a stack is due to the fact that we have access to only the element that is at the very top of the stack. Simply removing the items from the top of the stack is sufficient. Note: We can also choose to return the value of the element that was popped; however, how this is accomplished is entirely up to the discretion of the programmer implementing the code.

Peek: Return the top element of the stack without deleting it

The peek operation allows the user to see the element that is currently at the top of the stack of elements. There is no change to the stack of any kind during this procedure.

Working of Stack Data Structure

The following are the methods by which the procedures are carried out:

• In order to maintain track of which element is now at the top of the stack, a pointer named TOP is created
• During the initialization of the stack, we set its value to -1 in order to be able to identify whether or not the stack is empty by comparing the value of the TOP element
• We raise the value of TOP to its maximum value whenever an element is pushed. We then relocate the new element to the spot indicated by TOP
• When an element is popped, we return the element pointed to by TOP and reduce the value of the element that was previously popped
• Before attempting to push anything, we check to see if the stack has already been completed
• We first check to see if the stack has already been emptied before attempting to pop it

Conclusion

A stack is a conceptual structure that is composed of a collection of homogenous pieces and is based on the principle of last-in, first-out (LIFO). A typical abstract data type has two primary operations, push and pop, making it a popular choice for many applications. A stack is an abstract data type that has a predefined capacity and is used to store data. It enables the addition and removal of parts in a specific order. When an element is added to the stack, it is automatically moved to the top of the stack. A stack is a data structure that allows all operations to be performed at one end only.