83 lines
2.5 KiB
Python
83 lines
2.5 KiB
Python
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from typing import Tuple, List
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def browse_schema(schema):
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total_parts = 0
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buf = []
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max_row, max_col = len(schema), len(schema[0])
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for y in range(max_row):
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for x in range(max_col):
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item = schema[y][x]
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if item.isnumeric():
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# continue parsing full number
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buf.append(item)
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elif buf:
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# end of a number, do the engine part check
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if buf:
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neighbors = get_neighbors((x, y), len(buf), schema)
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if is_engine_part(neighbors):
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part_number = int("".join(buf))
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total_parts += part_number
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buf.clear() # reached end of a number, clear buffer
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print(f"Part 1, sum of the parts numbers = {total_parts}")
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print(f"Part 2, sum of the gear ratios = TODO")
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def is_engine_part(neighbors: List[str]) -> bool:
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# get list of symbols (not '.', \n or a number)
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symbols = filter(lambda x: not x.isnumeric() and not x in (".", "\n"), neighbors)
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return next(symbols, None) is not None
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def get_neighbors(pos: Tuple[int, int], length: int, schema: List[List[str]]) -> List[str]:
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x, y = pos
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start_x = x - length
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neighbors = [get_neighbors_of_digit((x, y), schema) for x in range(start_x, x)]
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neighbors = [item for sublist in neighbors for item in sublist] # flatten list of list
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return neighbors
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def get_neighbors_of_digit(pos: Tuple[int, int], schema: List[List[str]]) -> List[str]:
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max_row, max_col = len(schema), len(schema[0])
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x, y = pos
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neighbors = []
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# top
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if y-1 >= 0:
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neighbors.append(schema[y-1][x])
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# bottom:
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if y+1 < max_row:
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neighbors.append(schema[y+1][x])
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# left
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if x-1 >= 0:
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neighbors.append(schema[y][x-1])
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# right
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if x+1 < max_col:
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neighbors.append(schema[y][x+1])
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# top-left
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if y-1 >= 0 and x-1 >= 0:
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neighbors.append(schema[y-1][x-1])
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# top-right
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if y-1 >= 0 and x+1 < max_col:
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neighbors.append(schema[y-1][x+1])
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# bottom-left
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if y+1 < max_row and x-1 >= 0:
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neighbors.append(schema[y+1][x-1])
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# bottom-right
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if y+1 < max_row and x+1 < max_col:
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neighbors.append(schema[y+1][x+1])
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return neighbors
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if __name__ == "__main__":
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import sys
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infile = sys.argv[1]
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with open(infile) as f:
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schema = [[c for c in line] for line in f.readlines()]
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browse_schema(schema)
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