monotonic-stack 0.1.1

A monotonic stack

Monotonic Stack

The monotonic increasing stack and monotonic decreasing stack, namely monotonic stack, is a very powerful tool for finding next greater/smaller element. More specifically, always use monotonic increasing stack when we are trying to find the next smaller element, vice versa. The typical usage of monotonic stack is to find the next greater/smaller element in an array.

pip install monotonic_stack

This monotonic stack:

• works with any Python sequence, not just strings, if the items are hashable
• is implemented in pure Python

PyPi: https://pypi.org/project/monotonic-stack/

Usage

>>> from monotonic_stack import MonotonicStack
>>> MS = MonotonicStack([1, 2, 3, 4, 5])
>>> MS.next_greater_on_right()
[2, 3, 4, 5, -1]
>>> MS.next_greater_on_left()
[-1, 1, 2, 3, 4]
>>> MS.next_smaller_on_right()
[-1, -1, -1, -1, -1]
>>> MS.next_smaller_on_left()
[-1, -1, -1, -1, -1]