aoc/2022/22/solution.py

#!/usr/bin/python3
import sys

right, down, left, up = (1, 0), (0, 1), (-1, 0), (0, -1)
cube_regions = {
    1: [(50, 0), (99, 49)],
    2: [(100, 0), (149, 49)],
    3: [(50, 50), (99, 99)],
    4: [(0, 100), (49, 149)],
    5: [(50, 100), (99, 149)],
    6: [(0, 150), (49, 199)],
}
cube_transitions = {
    1: {
        right: (2, right, lambda x, y: (100, y)),
        down: (3, down, lambda x, y: (x, 50)),
        left: (4, right, lambda x, y: (0, 149 - y)),
        up: (6, right, lambda x, y: (0, 100 + x))
    },
    2: {
        right: (5, left, lambda x, y: (99, 149 - y)),
        down: (3, left, lambda x, y: (99, x - 50)),
        left: (1, left, lambda x, y: (99, y)),
        up: (6, up, lambda x, y: (x - 100, 199))
    },
    3: {
        right: (2, up, lambda x, y: (50 + y, 49)),
        down: (5, down, lambda x, y: (x, 100)),
        left: (4, down, lambda x, y: (y - 50, 100)),
        up: (1, up, lambda x, y: (x, 49))
    },
    4: {
        right: (5, right, lambda x, y: (50, y)),
        down: (6, down, lambda x, y: (x, 150)),
        left: (1, right, lambda x, y: (50, 149 - y)),
        up: (3, right, lambda x, y: (50, 50 + x))
    },
    5: {
        right: (2, left, lambda x, y: (149, 149 - y)),
        down: (6, left, lambda x, y: (49, 100 + x)),
        left: (4, left, lambda x, y: (49, y)),
        up: (3, up, lambda x, y: (x, 99))
    },
    6: {
        right: (5, up, lambda x, y: (y - 100, 149)),
        down: (2, down, lambda x, y: (100 + x, 0)),
        left: (1, down, lambda x, y: (y - 100, 0)),
        up: (4, up, lambda x, y: (x, 149))
    },
}

def wrap_around_position(grid, xlimits, ylimits, position, move):
    x, y = position
    mx, my = move
    #print(x, y, mx, my, '-> ', end='')
    # horizontal movement
    if mx > 0 and x + mx > xlimits[y][1]:
        x = xlimits[y][0]
        mx = 0
    elif mx < 0 and x + mx < xlimits[y][0]:
        x = xlimits[y][1]
        mx = 0
    # vertical movement
    if my > 0 and y + my > ylimits[x][1]:
        y = ylimits[x][0]
        my = 0
    elif my < 0 and y + my < ylimits[x][0]:
        y = ylimits[x][1]
        my = 0
    #print(x, y, mx, my)
    return (x + mx, y + my)

def wrap_around_position_cubic(grid, position, xlimits, move, side):
    x, y = position
    mx, my = move
    nx, ny = x + mx, y + my
    ul, lr = cube_regions[side]
    sx1, sy1 = ul
    sx2, sy2 = lr
    #print(x, y, mx, my, sx1, sy1, sx2, sy2)
    # horizontal cubic wrap around
    if abs(mx) > 0 and (nx < sx1 or nx > sx2):
        print('case 1 true')
        side, new_move, new_xy = cube_transitions[side][move]
        print(x, y, new_xy(nx, ny))
        x, y = new_xy(nx, ny)
        mx, my = new_move
    elif abs(my) > 0 and (ny < sy1 or ny > sy2):
        print('case 2 true')
        side, new_move, new_xy = cube_transitions[side][move]
        print(x, y, new_xy(nx, ny))
        x, y = new_xy(nx, ny)
        mx, my = new_move
    else:
        x = nx
        y = ny
    return (x, y), (mx, my), side

def collision(grid, xlimits, ylimits, position, cubic=False):
    x, y = position
    #print(x, y, xlimits[y][0], x - xlimits[y][0], len(grid), len(grid[y]))
    return grid[y][x - xlimits[y][0]] == '#'

def solution(cubic=False):
    path = None
    grid = []
    xlimits = []
    ylimits = []
    print(cube_regions)
    print(cube_transitions)
    side = 1

    for line in sys.stdin:
        stripped = line.strip()
        if stripped == '':
            path = next(sys.stdin).strip()
        else:
            offset = line.rstrip().count(' ')
            grid.append(stripped)
            xlimits.append((offset, offset + len(stripped) - 1))
    
    maxxl = 0
    for xl in xlimits:
        maxxl = max(maxxl, xl[1])
    for x in range(maxxl + 1):
        offset = 0
        count = 0
        count_offset = True
        for xl in xlimits:
            if count_offset:
                if x >= xl[0] and x <= xl[1]:
                    count_offset = False
                else:
                    offset += 1
            else:
                if x >= xl[0] and x <= xl[1]:
                    count += 1
        ylimits.append((offset, offset + count))

    print(grid)
    print(xlimits)
    print(ylimits)
    print(path)
    position = (xlimits[0][0], 0)
    facing = (1, 0)
    path = [[int(num) for num in p.split('L')] for p in path.split('R')]

    for i, rmove in enumerate(path):
        for j, lmove in enumerate(rmove):
            print(f'moving {lmove} (now at position {position} facing {facing} on side {side})')
            for k in range(int(lmove)):
                if not cubic:
                    next_position = wrap_around_position(grid, xlimits, ylimits, position, facing)
                    if not collision(grid, xlimits, ylimits, next_position):
                        position = next_position
                    else:
                        break
                else:
                    next_position, next_face, next_side = wrap_around_position_cubic(grid, position, xlimits, facing, side)
                    if not collision(grid, xlimits, ylimits, next_position):
                        position = next_position
                        facing = next_face
                        side = next_side
                    else:
                        break
            print(position)
            if j != len(rmove) - 1:
                facing = (facing[1], -facing[0])
                print(f'turning left (now facing {facing})')
        if i != len(path) - 1:
            facing = (-facing[1], facing[0])
            print(f'turning right (now facing {facing})')
    
    facing_number = {(1, 0): 0, (0, 1): 1, (-1, 0): 2, (0, -1): 3}
    password = 1000 * (position[1] + 1) + 4 * (position[0] + 1) + facing_number[facing]
    print(f'the password is {password}')

if sys.argv[1] in '1':
    solution()
else:
    solution(cubic=True)