75 lines
2.5 KiB
Python
75 lines
2.5 KiB
Python
def parse_file(file_path):
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"""Parse the input file to extract instructions and the node map."""
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try:
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with open(file_path, 'r') as file:
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lines = file.readlines()
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instructions = lines[0].strip()
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node_map = {}
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for line in lines[2:]:
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node, neighbors = line.strip().split(' = ')
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node_map[node] = tuple(neighbors[1:-1].split(', '))
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return instructions, node_map
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except Exception as e:
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print(f"Error parsing file {file_path}: {e}")
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raise
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def find_repeating_unit(sequence):
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"""Find the repeating unit in a sequence."""
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for i in range(1, len(sequence) + 1):
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unit = sequence[:i]
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if sequence == unit * (len(sequence) // len(unit)):
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return unit
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return sequence
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def navigate_network(instructions, node_map, start_node='AAA', end_node='ZZZ'):
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"""Navigate the network based on the instructions and return the number of steps."""
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current_node = start_node
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steps = 0
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visited = set()
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instruction_index = 0
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instructions = find_repeating_unit(instructions)
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while current_node != end_node:
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if (current_node, instruction_index) in visited:
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print(f"Loop detected at {current_node} with instruction index {instruction_index}")
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return -1 # Indicates a loop without reaching the end node
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visited.add((current_node, instruction_index))
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direction = instructions[instruction_index % len(instructions)]
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current_node = node_map[current_node][0 if direction == 'L' else 1]
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instruction_index += 1
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steps += 1
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return steps
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def run_test():
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"""Run the test with the provided file path."""
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try:
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expected_result = 6
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instructions, node_map = parse_file("../test.txt")
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result = navigate_network(instructions, node_map)
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assert result == expected_result, f"Test failed, expected {expected_result} but got {result}"
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print(f"Test passed with {result} steps.")
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except AssertionError as error:
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print(error)
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def main():
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print("Start Tests")
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run_test()
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try:
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print("Start input.txt")
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instructions, node_map = parse_file("../input.txt")
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result = navigate_network(instructions, node_map)
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if result == -1:
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print("Failed to reach the end node due to a loop.")
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else:
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print(f"Reached the end node in {result} steps.")
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except Exception as e:
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print(f"Error during main execution: {e}")
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if __name__ == "__main__":
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main()
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