A Stack is an abstract data type that serves as a collection of elements, with two principal operations: push, which adds an element to the collection, and pop, which removes the most recently added element that was not yet removed. The order in which elements come off a Stack gives rise to its alternative name, LIFO (for last in, first out). From Wikipedia
A Stack often has a third method peek which allows to check the last pushed element without popping it.
Average
| Access | Search | Insertion | Deletion |
|---|---|---|---|
| O(n) | O(n) | O(1) | O(1) |
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