Solution to advent of code - Day 12 - Part 2

advent_of_code_d12_p2.py

#aoc_d12.py
import re

inp = open('input_d12.txt','r').readlines()
#inp = ["0 <-> 2","1 <-> 1", "2 <-> 0, 3, 4", "3 <-> 2, 4", "4 <-> 2, 3, 6", "5 <-> 6", "6 <-> 4, 5"]

count = 0
connections = {}
visited = []
groups = [None]*len(inp)

def check(items):
	#print 'itms:',items#, groups
	if items in groups:
		return items
	#	#print 'yup'
	#	return items
	if type(items) is int and items not in visited:
		#print 'loop for ',items,visited
		visited.append(items)
		r = check(connections[items])
		#visited.remove(items)
		#print 'loop result:',r
		return r
	elif type(items) is int and items in visited:
		#print '=> ',items, visited
		return items
	
	#print 'moar check'
	w = []
	for i in items:
		#print 'loop for ',i,visited
		r = check(i)
		if type(r) is int:
			w.append(r)
	#print set(w)
	#print '=> f2'
	return next(iter(set(w)))


for i in inp:
	if "," in i:
		m = re.match("(\d+)\s<->\s([0-9,\s]+)",i)
		#print i
		i1 = int(m.group(1))
		#print m.group(2)
		items = [int(e) for e in m.group(2).split(',')]
		connections[i1] = items
		#for it in items:
		#	connections[it] = i1
	if "," not in i:
		m = re.match("(\d+)\s<->\s(\d+)",i)
		i1 = int(m.group(1))
		i2 = int(m.group(2))
		if i1 in connections:
			connections[i1].append(i2)
		else:
			connections[i1] = [i2]
		if i2 in connections:
			connections[i2].append(i1)
		else:
			connections[i2] = [i1]


for k in connections:
	visited = []
	#if connections[k] is int and connections[k] == k:
		#print "+1 for k=",k
	#	groups[k] = +1
	#else:
	#print k
	visited.append(k)
	r = check(connections[k])
	if type(r) is int:
		#print "k",k,"ended up in:",r
		groups[k] = r
	else:
		pass#print "no for k=",k
	#print '-----'

#print groups
print set(groups)