Samuel Enocsson
64 lines
1.6 KiB
Python
64 lines
1.6 KiB
Python
"""Day 11: Advent of Code 2025."""
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import time
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from collections import defaultdict
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from aoc import read_lines
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def build_graph(data: list[str]) -> dict[str, set[str]]:
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"""Build graph from input: 'fxp: udl vii hgb qmy' -> adjacency dict."""
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graph = defaultdict(set)
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for line in data:
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node, neighbors = line.split(': ')
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for neighbor in neighbors.split():
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graph[node].add(neighbor)
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return graph
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def count_paths(node, target, graph, memo={}):
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if node == target:
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return 1
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if node in memo:
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return memo[node]
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total = 0
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for neighbor in graph[node]:
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total += count_paths(neighbor, target, graph, memo)
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memo[node] = total
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return total
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def part1(data):
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"""Solve part 1."""
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graph = build_graph(data)
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count = count_paths("you", "out", graph)
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return count
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def part2(data):
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"""Solve part 2."""
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graph = build_graph(data)
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c1 = count_paths("svr", "dac", graph, {})
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c2 = count_paths("dac", "fft", graph, {})
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c3 = count_paths("fft", "out", graph, {})
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c4 = count_paths("svr", "fft", graph, {})
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c5 = count_paths("fft", "dac", graph, {})
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c6 = count_paths("dac", "out", graph, {})
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return (c1 * c2* c3) + (c4*c5*c6)
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if __name__ == "__main__":
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DAY = 11
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data = read_lines(DAY)
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t0 = time.perf_counter()
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p1 = part1(data)
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t1 = time.perf_counter()
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print(f"Part 1: {p1} ({(t1-t0)*1000:.2f} ms)")
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t0 = time.perf_counter()
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p2 = part2(data)
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t1 = time.perf_counter()
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print(f"Part 2: {p2} ({(t1-t0)*1000:.2f} ms)")
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