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84 lines
2.1 KiB
Python
84 lines
2.1 KiB
Python
3 years ago
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"""Solution for 2020/24"""
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from collections import defaultdict
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instructions = []
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with open('input', 'r') as f:
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for line in f.readlines():
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line = line.strip()
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i = 0
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instruction = []
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while i < len(line):
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if line[i] in ['w', 'e']:
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instruction.append(line[i])
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else:
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instruction.append(line[i:i+2])
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i += 1
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i += 1
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instructions.append(instruction)
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print(instructions)
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MOVEMENTS = {
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'e': (1, 0),
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'w': (-1, 0),
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'ne': (0, 1),
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'sw': (0, -1),
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'nw': (-1, 1),
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'se': (1, -1),
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}
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MOVES = 100
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def main():
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flipped_tiles = defaultdict(int)
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for instruction in instructions:
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coord = parse_instruction(instruction)
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flipped_tiles[coord] += 1
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print(''.join(instruction), coord)
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blacks = set([x[0] for x in flipped_tiles.items() if x[1] % 2 == 1])
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for day in range(MOVES):
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new_blacks = set()
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bbox = get_bbox(blacks)
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for x in range(bbox[0] - 1, bbox[2] + 2):
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for y in range(bbox[1] - 1, bbox[3] + 2):
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coord = (x, y)
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neighbors = get_neighbors(coord)
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adj_blacks = len([x for x in neighbors if x in blacks])
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is_black = coord in blacks
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if is_black and adj_blacks in [1, 2]:
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new_blacks.add(coord)
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elif not is_black and adj_blacks == 2:
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new_blacks.add(coord)
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blacks = new_blacks
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print(f'Day {day+1:>3}: {len(blacks)}')
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def parse_instruction(instruction):
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coord = (0, 0)
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for move in instruction:
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dx, dy = MOVEMENTS[move]
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coord = (coord[0] + dx, coord[1] + dy)
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return coord
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def get_bbox(coords):
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x_coords = list(map(lambda coord: coord[0], coords))
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y_coords = list(map(lambda coord: coord[1], coords))
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return min(x_coords), min(y_coords), max(x_coords), max(y_coords)
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def get_neighbors(coord):
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neigh = []
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for dx, dy in MOVEMENTS.values():
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neigh.append((coord[0] + dx, coord[1] + dy))
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return neigh
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main()
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