AoC2022 Day 22

#!/bin/python3

from io import StringIO
import re

testdata = """        ...#
        .#..
        #...
        ....
...#.......#
........#...
..#....#....
..........#.
        ...#....
        .....#..
        .#......
        ......#.

10R5L5R10L4R5L5"""

moves = None
field = []

joins = {}

def join(edge1, edge2, dir1, dir2):
    r1 = iter(edge1)
    r2 = iter(edge2)
    while True:
        try:
            p1 = next(r1)
            p2 = next(r2)
        except StopIteration:
            break
        joins[(p1,dir1)] = (p2,dir2)
        joins[(p2,(dir2+2)%4)] = (p1,(dir1+2)%4)


def ground(pos):
    return field[pos[0]][pos[1]]

def neigh(pos,dir):
    if (pos,dir) in joins:
        return joins[(pos,dir)]
    w = len(field[0])
    h = len(field)
    if dir==0: #right
        return ((pos[0],(pos[1]+1)%w), dir)
    elif dir==1: #down
        return (((pos[0]+1)%h,pos[1]), dir)
    elif dir==2: #left
        return ((pos[0], (pos[1]-1)%w), dir)
    elif dir==3: #up
        return (((pos[0]-1)%h,pos[1]), dir)
    else: #default
        return (pos, dir)

def move(pos,dir):
    n, ndir = neigh(pos,dir)
    if ground(n) == " ":
        while ground(n) == " ":
            n, ndir = neigh(n,ndir)

    if ground(n) == ".":
        return (n, ndir)
    elif ground(n) == "#":
        return (pos, dir)


with open("day22-input.txt",'r') as f:
#with StringIO(testdata) as f:
    while l := f.readline():
        if l[0] == '\n':
            continue
        elif l[0].isnumeric():
            moves_orig = l
        else:
            field.append(l[:-1])

width = max(map(len, field))
field = [" "*(width+2), *[f" {l}".ljust(width+2) for l in field], " "*(width+2)]

start = (1, field[1].find('.'))
pos = start
moves = moves_orig
dir = 0

while m := re.match(r"(\d+)(.*)", moves):
    moves = m.group(2)
    for _ in range(int(m.group(1))):
        pos, dir = move(pos,dir)
    if m:= re.match(r"([RL])(.*)", moves):
        moves = m.group(2)
        if m.group(1) == "R":
            dir = (dir+1)%4
        elif m.group(1) == "L":
            dir = (dir-1)%4
        else:
            raise Exception(f"Unknown direction token: {m.group(1)}")
    else:
        print(f"No more direction tokens, remaining string: '{moves}'")

print(dir, pos)
print(1000*pos[0]+4*pos[1]+dir)

# join to cube (hardcoded)

#       a    b
#     f        c
#            d
#     g    d
#   g
# f        c
#        e
# a    e
#   b

#a
join([(1, x) for x in range(51,101)], [(y, 1) for y in range(151,201)], 3, 0)
#b
join([(1, x) for x in range(101,151)], [(200, x) for x in range(1,51)], 3, 3)
#c
join([(y, 150) for y in range(1,51)], [(y, 100) for y in range(150,100,-1)], 0, 2)
#d
join([(50, x) for x in range(101,151)], [(y, 100) for y in range(51,101)], 1, 2)
#e
join([(150, x) for x in range(51,101)], [(y, 50) for y in range(151,201)], 1, 2)
#f
join([(y, 1) for y in range(101,151)], [(y, 51) for y in range(50,0,-1)], 2, 0)
#g
join([(101, x) for x in range(1,51)], [(y, 51) for y in range(51,101)], 3, 0)


pos = start
dir=0
moves = moves_orig

while m := re.match(r"(\d+)(.*)", moves):
    moves = m.group(2)
    for _ in range(int(m.group(1))):
        pos, dir = move(pos,dir)
    if m:= re.match(r"([RL])(.*)", moves):
        moves = m.group(2)
        if m.group(1) == "R":
            dir = (dir+1)%4
        elif m.group(1) == "L":
            dir = (dir-1)%4
        else:
            raise Exception(f"Unknown direction token: {m.group(1)}")
    else:
        print(f"No more direction tokens, remaining string: '{moves}'")

print(dir, pos)
print(1000*pos[0]+4*pos[1]+dir)