Function advent_of_code_2023::day_8::count_parallel_steps

fn count_parallel_steps(
    instructions: &Vec<Instruction>,
    network: &HashMap<&'_ str, (&'_ str, &'_ str)>
) -> usize

Given a ghost starts at each of the nodes ending in A, and each follows the instructions in parallel, how many steps until they are all on a terminal node at the same time.

The ghosts each follow a fixed cycle of steps, so this can be determined using the least common multiple of each of their cycle lengths