aoc-2021/08_day/code.py

import fileinput
import itertools

# key: the digit, value: the number of segments
digit_segment_count = {
	0: 6,
	1: 2, #
	2: 5,
	3: 5,
	4: 4, #
	5: 5,
	6: 6,
	7: 3, #
	8: 7, #
	9: 6
}

unique_digit = { # easy digits: 1,4,7,8
	2: 1,
	4: 4,
	3: 7,
	7: 8
}

actual_digit = 'abcdefg'

actual_digit_mapping = {
	0: 'abcefg',
	1: 'cf',
	2: 'acdeg',
	3: 'acdfg',
	4: 'bcdf',
	5: 'abdfg',
	6: 'abdefg',
	7: 'acf',
	8: 'abcdefg',
	9: 'abcdfg'
}

# ab: digit 1
# dab: digit 7
# eafb: digit 4
# acedgfb: digit 8

def get_keys(d, value):
	keys = []
	ls = filter(lambda i: i[1] == value, list(d.items()))
	ls = map(lambda i: i[0], ls)
	return list(ls)

data = []
ex =[]
#ex = ['acedgfb cdfbe gcdfa fbcad dab cefabd cdfgeb eafb cagedb ab | cdfeb fcadb cdfeb cdbaf']
for line in ex+list(fileinput.input()):
	content = line.strip()
	if content == '': continue

	def parse(x):
		l = map(str, x.split(' '))
		l = filter(lambda x: x != '', l)
		return list(l)

	ls = list(map(parse, content.split('|')))
	data.append((ls[0], ls[1]))

def part_1():
	count = 0
	for _,output in data:
		for x in output:
			out = get_keys(digit_segment_count, len(x))
			if len(out) == 1:
				count += 1
	return count

def is_similar(a, b):
	return set(list(a)) == set(list(b))

#print(part_1())

def find_by_length(ls, length):
	return list(filter(lambda x: len(x) == length, ls))[0]

def diff_str(a, b):
	commons = []
	longest,shortest = a, b
	if len(b) > len(a): longest, shortest = b, a
	for e in longest:
		if e in shortest:
			commons.append(e)
	all_d = list(set(a+b))
	diff = []
	for e in all_d:
		if e not in commons:
			diff.append(e)
	return diff

def remove_char_from_str(subject, char):
	return ''.join(list(filter(lambda x: x != char, subject)))

def remove_set(subject, char_set):
	return ''.join(list(filter(lambda x: not (x in char_set), subject)))

def remove_char_to_entry(entry, char):
	new_entry = []
	for e in entry:
		new_entry.append(e.replace(char, ''))
	return new_entry

# return true  
def included_in_str(subject, char_set):
	pass


def process_entry(entry):
	str_3 = find_by_length(entry, 3)
	str_2 = find_by_length(entry, 2)
	a = diff_str(str_3, str_2)[0]
	cf = str_2
	# on récupère le bd à partir du 4
	str_4 = find_by_length(entry, 4)
	bd = remove_set(str_4, cf)
	
	# enlever a
	entry = remove_char_to_entry(entry, a)

	# trouver g
	# trouver le str_5 qui continent cf et bd
	str_5 = list(
		filter(
			lambda x: included_in_str(x, cf+bd),
			find_by_length(entry, 5)
		))
	print(str_5)

	return entry

def digit_with_mapping(mapping, digit):
	assert(digit in actual_digit_mapping)
	actual = actual_digit_mapping[digit]

	encoded = [mapping[actual_digit.index(a)] for i,a in enumerate(actual)]
	return ''.join(encoded)


def process_entry_force(entry):
	sets = [set(s) for s in entry]
	poss = list(itertools.permutations('abcdefg'))
	for p in poss:
		# we do an hypothesis that poss is the mapping
		mapping = ''.join(p)
		ok = True
		for d in range(10):
			s = set(digit_with_mapping(mapping, d))
			if not (s in sets):
				ok = False
				break
		if ok:
			return mapping

def compute_output(mapping, segments):
	def match(w):
		i = mapping.index(w)
		return actual_digit[i]
	a = list(map(match, segments))
	a = list(sorted(a))
	key = ''.join(a)
	d = get_keys(actual_digit_mapping, key)[0]
	return d


def part_2():
	res = 0
	for entry in data:
		mapping = process_entry_force(entry[0])
		val = int(
			''.join([str(compute_output(mapping, d)) for d in entry[1]])
		)
		print(f'{mapping=} {val=}')
		res += val
	print(res)


print(part_2())

"""
{dab} = {acf}
{ab} = {cf}

so d = a


using the "unique signal patterns" hypothesis will give:

0,1,2,3,4,5,6,7,8,9

on enlève les digits faciles (1,4,7,8) 

1 = cf
4 = bcdf
7 = acf
8 = abcdefg

il reste donc 0,2,3,5,6,9

"""