Solution to Day 13: Packet Scanners - Part 2

advent_of_code_d13_p2.py

#aoc_d13.py

inp = ["0: 3","1: 2","4: 4","6: 4"]
inp = open('input_d13.txt','r').readlines()
data = [d.split(':') for d in inp]

dic = {}
data = dict(data)


maximum = int(max(data))+1
direction = [1]*maximum
pos = [0]*maximum

def setup():
	for i in range(maximum):
		if str(i) in data:
			scanners[i] = [None]*int(data[str(i)])
			direction[i] = 1
		else:
			scanners[i] = [None]
			direction[i] = 0

	for i in range(maximum):
		if scanners[i] != [None]:
			scanners[i][0] = 'S'

def operate(pos, scanners, direction):
	for k in range(len(pos)):
		#print scanners,pos
		scanners[k][pos[k]] = None
		pos[k] += direction[k]
		if pos[k] + direction[k] >= len(scanners[k]):
			direction[k] *= -1
		elif pos[k] + direction[k] < 0:
			direction[k] *= -1
		if scanners[k] != [None]:
			#print 'upd for ',k,pos[k]
			scanners[k][pos[k]] = 'S'

scanners = [None]*maximum

setup()

copy = scanners
caught = 0
delay = 0
max_scanner = 0
last_executed = copy
last_directions = direction
last_pos = pos
print 'Len:',len(scanners)
while True:
	caught = 0
	#scanners = copy
	#direction = [1]*maximum
	#pos = [0]*maximum
	#setup()
	#print 'delay', delay
	if delay != 0:
		scanners = list(last_executed)
		direction = list(last_directions)
		pos = list(last_pos)
		#print 'bef:',delay,scanners
		operate(pos, scanners, direction)
		#print 'aft:',delay,scanners
		last_executed = list(scanners)
		last_directions = list(direction)
		last_pos = list(pos)
	#print 'delayed by: ',delay,scanners
	for i in range(maximum):
		if scanners[i][0] == 'S':
			if max_scanner < i:
				max_scanner = i
				print 'max: ',max_scanner, 'delay: ',delay
			#print 'have it on pos: ',i
			caught = 1
			break
		operate(pos, scanners, direction)
	if caught == 0:
		print delay
		break
	else:
		delay += 1
	#if delay > 15:
	#	break

print delay
#print caught