91 lines
2.7 KiB
Python
Executable file
91 lines
2.7 KiB
Python
Executable file
#!/usr/bin/env python3
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# https://adventofcode.com/2024/day/8
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from itertools import combinations
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def get_lines(filename: str) -> list:
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with open(filename, "r") as file:
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return [line.strip() for line in file.readlines()]
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def get_antenna_groups(lines: list) -> dict:
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antenna_groups = {}
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for row, line in enumerate(lines):
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for col, char in enumerate(line):
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if char != ".":
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if char not in antenna_groups:
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antenna_groups[char] = [(row, col)]
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else:
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antenna_groups[char].append((row, col))
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return antenna_groups
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def get_anti_nodes(pair: tuple, max_row: int, max_col: int) -> set:
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anti_nodes = set()
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a, b = pair
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a_row, a_col = a
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b_row, b_col = b
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vektor_row = b_row - a_row
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vektor_col = b_col - a_col
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anti_a_row = a_row - vektor_row
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anti_a_col = a_col - vektor_col
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if 0 <= anti_a_row <= max_row and 0 <= anti_a_col <= max_col:
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anti_nodes.add((anti_a_row, anti_a_col))
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anti_b_row = b_row + vektor_row
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anti_b_col = b_col + vektor_col
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if 0 <= anti_b_row <= max_row and 0 <= anti_b_col <= max_col:
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anti_nodes.add((anti_b_row, anti_b_col))
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return anti_nodes
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def print_field(antennas: list, new_anti_nodes: set, max_row: int, max_col: int) -> None:
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field = []
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for i in range(max_row + 1):
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row = []
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for j in range(max_col + 1):
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row.append(".")
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field.append(row)
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for antenna in antennas:
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row, col = antenna
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field[row][col] = "A"
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for anti_node in new_anti_nodes:
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row, col = anti_node
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if field[row][col] == "A":
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field[row][col] = "@"
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else:
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field[row][col] = "#"
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for row in field:
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for char in row:
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print(char, end="")
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print()
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print()
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def get_all_anti_nodes(antenna_groups: dict, max_row: int, max_col: int) -> set:
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anti_nodes = set()
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for antenna_group in antenna_groups:
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antennas = antenna_groups[antenna_group]
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antenna_pairs = combinations(antennas, 2)
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for pair in antenna_pairs:
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new_anti_nodes = get_anti_nodes(pair, max_row, max_col)
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anti_nodes.update(new_anti_nodes)
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# print_field(antennas, anti_nodes, max_row, max_col)
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return anti_nodes
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def main():
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# lines = get_lines("sample-input.txt")
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# lines = get_lines("sample-input2.txt")
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lines = get_lines("input.txt")
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antenna_groups = get_antenna_groups(lines)
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max_row = len(lines) - 1
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max_col = len(lines[0]) - 1
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anti_nodes = get_all_anti_nodes(antenna_groups, max_row, max_col)
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print(f"Part 1: There are {len(anti_nodes)} anti-nodes on the map.")
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if __name__ == '__main__':
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main()
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