Bit-based universe simulation
You are representing each state of the universe as a list of bits. However, CPUs are experts at handling sequences of bits — that's what an integer is!

Given two bits, the way to find out whether exactly one of them is 1 is to use the ^ operator (XOR).

You should be able to solve this challenge using bit-shifting (&lt;&lt; and &gt;&gt; operators) and ^.