40 lines
710 B
Python
40 lines
710 B
Python
import sys
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input = sys.stdin.readline
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print = sys.stdout.write
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N = int(input())
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def solve(N: int) -> int:
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count = 0
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D = []
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for i in range(N):
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T = [i]
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D.append((1, T))
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while D:
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now, xs = D.pop()
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if now == N:
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count += 1
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continue
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for i in range(N):
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if i in xs:
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continue
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flag = True
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for j in range(now):
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y = xs[j]
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if abs(now - j) == abs(y - i):
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flag = False
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break
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if flag:
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D.append((now + 1, xs + [i]))
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return count
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if __name__ == "__main__":
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print(str(solve(N)))
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