21 lines
535 B
Text
21 lines
535 B
Text
(de quadruples (N)
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(let (AB NIL S 3 R)
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(for A N
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(for (B A (>= N B) (inc B))
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(idx
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'AB
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(+ (* A A) (* B B))
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T ) ) )
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(for C N
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(let (S1 S S2)
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(inc 'S 2)
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(setq S2 S)
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(for (D (+ C 1) (>= N D) (inc D))
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(and (idx 'AB S1) (idx 'R D T))
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(inc 'S1 S2)
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(inc 'S2 2) ) ) )
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(make
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(for A N
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(or (idx 'R A) (link A)) ) ) ) )
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(println (quadruples 2200))
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