aoc/2022/day15.py
2023-04-17 20:18:20 +02:00

101 lines
2.7 KiB
Python
Executable file

#!/bin/bash
# thanks github.com/bernadetten
import sys
import re
from itertools import pairwise
test = bool(int(sys.argv[1]))
file_path = ""
data = ""
prodata = []
given_y = [int(sys.argv[2])]
absent_points = []
part1 = bool(int(sys.argv[3]))
max_y = int(sys.argv[4])
if test:
file_path = "test_day_15.txt"
else:
file_path = "input_day_15.txt"
with open(file_path, "r") as f:
data = f.read().split("\n")
# The anhatten distance
def md(x1, y1, x2, y2):
return abs(x1 - x2) + abs(y1 - y2)
# Processing the data.
for line in data:
if line != "":
m = re.match(
r"Sensor at x=(?P<sx>-?\d+), y=(?P<sy>-?\d+): closest beacon is at x=(?P<bx>-?\d+), y=(?P<by>-?\d+)",
line.strip(),
)
x_s = int(m.group("sx"))
y_s = int(m.group("sy"))
x_b = int(m.group("bx"))
y_b = int(m.group("by"))
dis = md(x_s, y_s, x_b, y_b)
prodata += [((x_s, y_s), (x_b, y_b), dis)]
# All y-values we want to loop over if part 2
if not part1:
given_y = [x for x in range(0, max_y + 1)]
# Merge all ranges
def mergeranges(ranges):
super_range = ranges[0]
ranges = ranges[1:]
for (xl, xh) in ranges:
# print('super', super_range)
#print('comparing to', xl, ' ', xh)
if not (xl - 1 <= super_range[1] and xl >= super_range[0]):
return xl - 1
if xh > super_range[1]:
super_range = (super_range[0], xh)
return None
# Now we calculate the impossible ranges
for y in given_y:
if part1:
beacon_on_y = [b[0] for _, b, _ in prodata if b[1] == y]
absent_points = []
#print(y)
# We need to add the ranges of points that are not available.
for source, beacon, dis in prodata:
height_diff = abs(source[1] - y)
remain_dist = dis - height_diff
if remain_dist >= 0:
# print('Source ', source, ' y ', y, ' dis ', dis, ' diff ', height_diff)
lower_x = source[0] - remain_dist
higher_x = source[0] + remain_dist
if part1:
absent_points += [
x for x in range(lower_x, higher_x + 1) if x not in beacon_on_y
]
else:
absent_points += [(lower_x, higher_x)]
# If we are doing part two we need to post process the output per line.
if not part1:
# print(absent_points)
absent_points = sorted(absent_points)
#print(absent_points)
result = mergeranges(absent_points)
if result != None:
print('part2, x:', result, 'y:', y, 'output:', result *4000000 +y)
sys.exit()
if part1:
print('part1', len(set(absent_points)))