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- text = open(0).read()
- graph = {
- complex(x, y): int({'.': 1, '#': 10000}.get(val, val))
- for y, row in enumerate(text.splitlines())
- for x, val in enumerate(row)
- }
- xmax = max(int(p.real) for p in graph)
- ymax = max(int(p.imag) for p in graph)
- end = complex(xmax, ymax)
- mapping = {1: '>', -1: '<', 1j: 'v', -1j: '^'}
-
- # a position mapped to the lowest effort taken to reach it
- edge = {(0, ''): (0, '')}
- exhausted = {}
- while end not in exhausted:
- pos = min(edge, key=edge.get)
- parent = edge.pop(pos)
- if pos[0] == end:
- break
- exhausted[pos] = parent
- for step in [1, -1, 1j, -1j]:
- # no reverse
- if pos[1] and pos[1][-1] == mapping[-step]: continue
-
- # turn condition
- bop = pos[1] + mapping[step]
- if len(bop) == 4 and len(set(bop)) == 1: continue
-
- adj = pos[0] + step, bop[-3:]
-
- # out of bounds check
- if adj[0] not in graph: continue
-
- # some positions are truly dead
- if adj in exhausted: continue
-
- score = parent[0] + graph[adj[0]], parent[1] + mapping[step]
- if adj not in edge:
- edge[adj] = score
- else:
- edge[adj] = min(edge[adj], score)
-
-
- def scorer(seq):
- pos = 0
- out = 0
- for char in seq:
- pos += {'>': 1, '<': -1, '^': -1j, 'v': 1j}[char]
- out += graph[pos]
- return out
-
-
- print(parent[1], scorer(parent[1]))
- test = '>>>v>>>^>>>vv>vv>vvv>vvv<vv>'
- print(test, scorer(test))
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