Stack Algorithms

A stack is an important data structure based on the LIFO (Last In, First Out) principle. This means that the item that is put into the stack last is the first one to be taken out. There are some key algorithms for the operation of a stack, such as Push, Pop, Peek, and Is-Empty.

The push operation is used to add a new element to the top of the stack.

Algorithm:

1. If the stack is full (Stack Overflow), the algorithm cannot insert a new item and displays an error.
2. If there is space in the stack, the top position of the stack is incremented by one.
3. The given element is inserted at the new top position of the stack.

The pop operation is used to remove an element from the top of the stack.

Algorithm:

1. If the stack is empty (Stack Underflow), no element can be removed, and an error is displayed.
2. If there are elements in the stack, the item from the top position is removed.
3. The top is decremented by one.

The peek operation is used to see which element is at the top of the stack without removing it.

Algorithm:

1. If the stack is empty, an error is displayed.
2. Otherwise, the element at the top position is returned.

The is-empty operation is used to check if the stack is empty or not.

Algorithm:

1. If `top == -1`, the stack is empty.
2. Otherwise, the stack contains elements.