aoc/2020/12/12.py

def read_file():
	with open("input.txt","r") as f:
		return f.read().split('\n')

def navigate(instructions):
	direction = "E"
	x = 0
	y = 0
	for instruction in instructions:
		action = instruction[0]
		value = int(instruction[1:])
		if action == "N":
			y += value
		elif action == "S":
			y -= value
		elif action == "E":
			x += value
		elif action == "W":
			x -= value
		elif action == "F":
			if direction == "N":
				y += value
			elif direction == "S":
				y -= value
			elif direction == "E":
				x += value
			elif direction == "W":
				x -= value
		elif action == "L":
			if direction == "E":
				if value == 90:
					direction = "N"
				elif value == 180:
					direction = "W"
				elif value == 270:
					direction = "S"
			elif direction == "N":
				if value == 90:
					direction = "W"
				elif value == 180:
					direction = "S"
				elif value == 270:
					direction = "E"
			elif direction == "W":
				if value == 90:
					direction = "S"
				elif value == 180:
					direction = "E"
				elif value == 270:
					direction = "N"
			elif direction == "S":
				if value == 90:
					direction = "E"
				elif value == 180:
					direction = "N"
				elif value == 270:
					direction = "W"
		elif action == "R":
			if direction == "E":
				if value == 90:
					direction = "S"
				elif value == 180:
					direction = "W"
				elif value == 270:
					direction = "N"
			elif direction == "S":
				if value == 90:
					direction = "W"
				elif value == 180:
					direction = "N"
				elif value == 270:
					direction = "E"
			elif direction == "W":
				if value == 90:
					direction = "N"
				elif value == 180:
					direction = "E"
				elif value == 270:
					direction = "S"
			elif direction == "N":
				if value == 90:
					direction = "E"
				elif value == 180:
					direction = "S"
				elif value == 270:
					direction = "W"
	return x, y, direction

def navigate2(instructions):
	x = 0
	y = 0
	wx = 10
	wy = 1
	for instruction in instructions:
		action = instruction[0]
		value = int(instruction[1:])
		if action == "N":
			wy += value
		elif action == "S":
			wy -= value
		elif action == "E":
			wx += value
		elif action == "W":
			wx -= value
		elif action == "F":
			x += value * wx
			y += value * wy
		elif action == "L":
			if value == 90:
				wx, wy = -wy, wx
			elif value == 180:
				wx, wy = -wx, -wy
			elif value == 270:
				wx, wy = wy, -wx
		elif action == "R":
			if value == 90:
				wx, wy = wy, -wx
			elif value == 180:
				wx, wy = -wx, -wy
			elif value == 270:
				wx, wy = -wy, wx
	return x, y, wx, wy

def part1(instructions):
	x, y, direction = navigate(instructions)
	return abs(x) + abs(y)

def part2(instructions):
	x, y, wx, wy = navigate2(instructions)
	return abs(x) + abs(y)

def main():
	instructions = read_file()
	print(part1(instructions), part2(instructions))

if __name__ == "__main__":
	main()