def run() -> (int, int):
cups = [int(c) for c in read_as.lines("input/23.txt")[0]]
links_p1, links_p2 = Links(), Links()
for i in range(len(cups) - 1):
links_p1.set(cups[i], cups[i + 1])
links_p2.set(cups[i], cups[i + 1])
links_p1.set(cups[-1], cups[0])
links_p2.set(cups[-1], 10)
links_p2.set(1000000, cups[0])
links_p1.run(100, 9, cups[0])
links_p2.run(10000000, 1000000, cups[0])
p1 = 0
next_cup = links_p1.get(1)
while next_cup != 1:
p1 = (10 * p1) + next_cup
next_cup = links_p1.get(next_cup)
p2 = links_p2.get(1) * links_p2.get(links_p2.get(1))
return (p1, p2)
def run() -> (int, int):
lines = read_as.lines("input/14.txt")
results_p1, results_p2 = {}, {}
mask_bits_p1, mask_bits_p2 = [], []
for line in lines:
op, arg = line.split(" = ")
if op == "mask":
mask_bits_p1 = [(i, char) for (i, char) in enumerate(arg)
if char != "X"]
mask_bits_p2 = [(i, char) for (i, char) in enumerate(arg)
if char != "0"]
else:
index = int(op[4:-1])
# P1
bitstring = list("{0:036b}".format(int(arg)))
for (i, m) in mask_bits_p1:
bitstring[i] = m
results_p1[index] = int("".join(bitstring), 2)
# P2
indexstring = list("{0:036b}".format(index))
for (i, m) in mask_bits_p2:
indexstring[i] = m
for addr in all_perms(indexstring):
results_p2[int("".join(addr), 2)] = int(arg)
return (sum(results_p1.values()), sum(results_p2.values()))
def run() -> (int, int):
pub_1, pub_2 = [int(line) for line in read_as.lines("input/25.txt")]
m = 20201227
loop, n = 1, 1
while (n := (n * 7) % m) not in {pub_1, pub_2}:
loop += 1
def run() -> (int, int):
adapters = sorted([int(line) for line in read_as.lines("input/10.txt")])
jumps = Counter([adapters[i] - adapters[i-1] for i in range(1, len(adapters))])
jumps[adapters[0]] += 1
jumps[3] += 1
return(jumps[1] * jumps[3], paths_to_target(adapters))
def run() -> (int, int):
ship = Ship(1 + 0j, False)
ship_wp = Ship(10 + 1j, True)
for instr in read_as.lines("input/12.txt"):
command, val = instr[0], int(instr[1:])
ship.move(command, val)
ship_wp.move(command, val)
return (ship.manhattan(), ship_wp.manhattan())
def run() -> (int, int):
nums = [int(num) for num in read_as.lines("input/9.txt")]
window = 25
for i in range(window, len(nums)):
num = nums[i]
if sum_of_window(num, nums[i - window:i]) == False:
break
return (num, subseq_sum(num, nums))
def run() -> (int, int):
bags = {}
for line in read_as.lines("input/7.txt"):
(colour, contents) = line.split(" bags contain ")
bags[colour] = re.findall(r"([0-9]+) ([a-z ]+) bags?[,.]", contents)
bags_containing = sum([
contains_shiny_gold(colour, bags) for colour in bags
if colour != "shiny gold"
])
return (bags_containing, num_contents("shiny gold", bags) - 1)
def run() -> (int, int):
seat_indices = [
seat_to_index(seat) for seat in read_as.lines("input/5.txt")
]
max_seat = max(seat_indices)
min_seat = min(seat_indices)
seat_sum = sum(seat_indices)
missing_seat = sum(range(min_seat, max_seat + 1)) - seat_sum
return (max_seat, missing_seat)
def run() -> (int, int):
right = [1, 3, 5, 7, 1]
down = [1, 1, 1, 1, 2]
trees = [0, 0, 0, 0, 0]
r = 0
for row in read_as.lines("input/3.txt"):
for i in range(0, len(trees)):
if r % down[i] == 0:
trees[i] += row[(r * right[i] // down[i]) % len(row)] == "#"
r += 1
return (trees[1], prod(trees))
def run() -> (int, int):
lines = read_as.lines("input/13.txt")
departure_time = int(lines[0])
buses = [ (i, int(bus)) for (i, bus) in enumerate(lines[1].split(",")) if bus != "x"]
time_to_wait = math.inf
bus_to_take = 0
for (_, bus_num) in buses:
new_time = bus_num - (departure_time % bus_num)
if new_time < time_to_wait:
time_to_wait = new_time
bus_to_take = bus_num
# p2 == Chinese Remainder Theorem
return (time_to_wait * bus_to_take, 894954360381385)
def run() -> (int, int):
visited = set()
for path in read_as.lines("input/24.txt"):
north, east = 0, 0
for move in re.findall("[ns]?[ew]", path):
north, east = {
'e': (north, east + 2),
'ne': (north + 1, east + 1),
'se': (north - 1, east + 1),
'w': (north, east - 2),
'nw': (north + 1, east - 1),
'sw': (north - 1, east - 1)
}[move]
visited ^= {(north, east)}
return (len(visited), len(update(visited, 100)))
def run() -> (int, int):
lines = read_as.lines("input/21.txt")
possible = defaultdict(list)
all_ingreds = []
for line in lines:
ingredients, allergens = line.split("(contains")
ingredients = ingredients.strip().split(' ')
allergens = allergens.strip(' )').split(", ")
all_ingreds.extend(ingredients)
for allergen in allergens:
possible[allergen].append(set(ingredients))
possible = {a: set.intersection(*i) for (a, i) in possible.items()}
known_allergens = {}
while len(possible) > 0:
known = [(i, deepcopy(a).pop()) for (i, a) in possible.items()
if len(a) == 1]
for (known_a, known_i) in known:
known_allergens[known_a] = known_i
possible = {
a: {x
for x in i if x != known_i}
for (a, i) in possible.items() if a != known_a
}
total_non_allergens = len(
[i for i in all_ingreds if i not in known_allergens.values()])
canonical_danger_list = [
i for (a, i) in sorted(known_allergens.items(), key=lambda x: x[0])
]
return (total_non_allergens, ",".join(canonical_danger_list))
def run() -> (int, int):
lines = read_as.lines("input/18.txt")
total_p1 = sum(int(compute(line, False)) for line in lines)
total_p2 = sum(int(compute(line, True)) for line in lines)
return (total_p1, total_p2)
def run() -> (int, int):
nums = set(int(line) for line in read_as.lines("input/1.txt"))
return pair(nums, 2020).pop(), trips(nums, 2020).pop()