operator overloading, let, heightmap - Advent of Code 2021 - Day 9 with Ruby

Fixnum#between?, operator overloading, let, heightmap - Advent of Code 2021 - Day 9 with Ruby

00:00 Part 1
06:45 Fixnum#between? Check to see if a value is between two numbers
10:34 Operator overloading
12:40 using `let` with RSpec
19:00 Part 2