10 lines
914 B
FSharp
10 lines
914 B
FSharp
// Generate EKG Sequences. Nigel Galloway: December 6th., 2018
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let EKG n=seq{
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let fN,fG=let i=System.Collections.Generic.Dictionary<int,int>()
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let fN g=(if not (i.ContainsKey g) then i.[g]<-g);(g,i.[g])
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((fun e->i.[e]<-i.[e]+e), (fun l->l|>List.map fN))
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let fU l= pCache|>Seq.takeWhile(fun n->n<=l)|>Seq.filter(fun n->l%n=0)|>List.ofSeq
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let rec EKG l (α,β)=seq{let b=fU β in if (β=n||β<snd((fG b|>List.maxBy snd))) then fN α; yield! EKG l (fG l|>List.minBy snd)
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else fN α;yield β;yield! EKG b (fG b|>List.minBy snd)}
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yield! seq[1;n]; let g=fU n in yield! EKG g (fG g|>Seq.minBy snd)}
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let EKGconv n g=Seq.zip(EKG n)(EKG g)|>Seq.skip 2|>Seq.scan(fun(n,i,g,e)(l,β)->(Set.add l n,Set.add β i,l,β))(set[1;n],set[1;g],0,0)|>Seq.takeWhile(fun(n,i,g,e)->g<>e||n<>i)
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