17 lines
640 B
Text
17 lines
640 B
Text
NB. http://rosettacode.org/wiki/Mian-Chowla_sequence
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NB. Dreadfully inefficient implementation recomputes all the sums to n-1
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NB. and computes the full addition table rather than just a triangular region
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NB. However, this implementation is sufficiently quick to meet the requirements.
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NB. The vector head is the next speculative value
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NB. Beheaded, the vector is Mian-Chowla sequence.
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Until =: conjunction def 'u^:(0 = v)^:_'
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unique =: -:&# ~. NB. tally of list matches that of set
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next_mc =: [: (, {.) (>:@:{. , }.)Until(unique@:((<:/~@i.@# #&, +/~)@:(}. , {.)))
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prime_q =: 1&p: NB. for fun look at prime generation suitability
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