15_rambunctious_recitation.py

###########################################
# --- Day 15: Rambunctious Recitation --- #
###########################################

import AOCUtils

def memoryGame(start, n):
    seen = dict()
    last = None

    for i in range(n):
        if i < len(start):
            speak = start[i]
        elif len(seen[last]) < 2:
            speak = 0
        else:
            speak = seen[last][-1] - seen[last][-2]

        if speak not in seen:
            seen[speak] = []
        seen[speak].append(i)
        last = speak

    return speak

###########################################

start = AOCUtils.loadInput(15)

start = [int(i) for i in start.split(",")]

print("Part 1: {}".format(memoryGame(start, 2020)))

print("Part 2: {}".format(memoryGame(start, 30000000)))

AOCUtils.printTimeTaken()