ruby-stack

What

A simple Ruby implementation of a stack-like data structure that supports each of these operations in O(1) (constant time):

• push: add a value to the top of the stack
• pop: remove the top value from the stack, and return it
• size: return the number of values in the stack
• max: return the largest value currently in the stack, leaving the stack unchanged

Oh, okay

Ruby has a very reasonable dyanamic array implementation called Array. It's so reasonable, it even has push and pop methods! But we won't use those, and instead we'll make a C-like array implementation of a stack, but lean on the dynamic resizing properties of the built-in Array class. Life becomes difficult when you try to manage memory more closely than this in Ruby, and arguably you could use a more appropriate language if you cared to.

I want to run the tests

There are some minitest unit tests in stack_test.rb

gem install minitest
make test

Is the complexity O(1)?

There was an attempt to test this, with increasing array sizes. Try running

make complexity