A stack is an abstract data type that serves as a collection of elements.
LIFO (last in, first out)
...the push and pop operations occur only at one end of the structure, referred to as the top of the stack.
A common use of stacks at the architecture level is as a means of allocating and accessing memory e.g. call stack.
class Stack {
maxSize: number;
size: number;
items: any[];
}-
Backtracking - store points we have visited, e.g. depth-first search.
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Memory management - Almost all calling conventions—the ways in which subroutines receive their parameters and return results—use a special stack (the "call stack") to hold information about procedure/function calling and nesting in order to switch to the context of the called function and restore to the caller function when the calling finishes.
push- ...which adds an element to the collection.pop- ...which removes the most recently added element.
peek- Look at the top element without removing it.duplicate- The top item is popped, and then pushed again (twice), so that an additional copy of the former top item is now on top, with the original below it.swap- the two topmost items on the stack exchange places.rotate- the n topmost items are moved on the stack in a rotating fashion.