|
- import heapq
-
-
- def shortest_path(graph, X, Y):
- risk = {0: 0}
- seen = set()
- heap = [(0, '', 0)] # string disambiguates cost ties for imaginary numbers
-
- end = complex(X - 1, Y - 1)
- tip = 0
- while end not in seen:
- _, _, tip = heapq.heappop(heap)
- seen.add(tip)
- for y in (tip + dx for dx in [1, -1, 1j, -1j]):
- if y in graph:
- if y not in risk or risk[y] > graph[y] + risk[tip]:
- risk[y] = graph[y] + risk[tip]
- heapq.heappush(heap, (risk[y], str(y), y))
-
- return risk[end]
-
-
- graph = {}
- for y, line in enumerate(text.splitlines()):
- for x, char in enumerate(line):
- graph[complex(x, y)] = int(char)
- X, Y = x + 1, y + 1
-
- ans1 = shortest_path(graph, X, Y)
-
- graph = {
- pos + complex(X * dx, Y * dy): sum(divmod(graph[pos] + dx + dy, 10))
- for pos, value in graph.items()
- for dx in range(5)
- for dy in range(5)
- }
- ans2 = shortest_path(graph, 5 * X, 5 * Y)
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