binary and bit fiddling, xor, Array#median - Advent of Code - Day 3 in ruby

binary and bit fiddling, xor, Array#median - Advent of Code - Day 3 in ruby

00:30 Part 1
08:07 Using Fixnum#[] to access the bit value at an index
10:23 Numbered block argument
15:36 XOR exclusive or to flip bits
20:30 Part 2
24:30 Array#median monkey patch to find middle element