16 lines
319 B
Text
16 lines
319 B
Text
def queens(n):
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def sums:
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. as $board
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| [ range(0;length) | . + $board[.]]
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| unique | length;
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def differences:
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. as $board
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| [ range(0;length) | . - $board[.]]
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| unique | length;
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def allowable:
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length as $n
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| sums == $n and differences == $n;
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count( permutations(n) | select(allowable) );
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