"""
Chapter 10 - Problem 10.11 - Peaks and Valleys
Problem:
In an array of integers, a "peak" is an element which is greater than or equal to the adjacent integers and
a "valley" is an element which is less than or equal to the adjacent integers. For example, in the array
{5, 8, 6, 2, 3, 4, 6}, {8, 6} are peaks and {5, 2} are valleys. Given an array of integers, sort the array
into an alternating sequence of peaks and valleys.

"""
