Hi all !
My submission, see below.
Cheers,
Erling Hellenäs
RangeIndex=: ([ + [: i. ] - [) , ]
3 RangeIndex 11
NB. 3 4 5 6 7 8 9 10 11
8 RangeIndex 10
NB. 8 9 10
Primes=: (1 p: ]) # ]
Primes 3 4 5 6 7 8 9 10 11
NB. 3 5 7 11
Primes 8 9 10
NB. i.0
AddStartRangeIfNotThere=: (([ ~: 1 {. ]) # [) , ]
3 AddStartRangeIfNotThere 3 5 7 11
NB. 3 5 7 11
8 AddStartRangeIfNotThere i.0
NB. 8
AddEndRangeIfNotThere=: ] , ([ ~: _1 {. ]) # [
11 AddEndRangeIfNotThere 3 5 7 11
NB. 3 5 7 11
10 AddEndRangeIfNotThere 8
NB. 8 10
SequenceLengths=: 1 + (1 }. ]) - _1 }. ]
SequenceLengths 3 5 7 11
NB.3 3 5
SequenceLengths 8 10
NB. 3
FirstInLongestSequence=: '' $ (([ = [: >./ [) , 0:) # ]
3 3 5 FirstInLongestSequence 3 5 7 11
NB. 7
3 FirstInLongestSequence 8 10
NB. 8
SequenceIndices=: ] + [: i. [: >./ [
3 3 5 SequenceIndices 7
NB. 7 8 9 10 11
(,3) SequenceIndices 8
NB. 8 9 10
DropFirstIfPrime=: (1 p: 1 {. ]) }. ]
DropFirstIfPrime 7 8 9 10 11
NB. 8 9 10 11
DropFirstIfPrime 8 9 10
NB. 8 9 10
DropLastIfPrime=: (_1 * 1 p: _1 {. ]) }. ]
DropLastIfPrime 8 9 10 11
NB. 8 9 10
DropLastIfPrime 8 9 10
NB. 8 9 10
f=:[: DropLastIfPrime [: DropFirstIfPrime [: ( SequenceLengths ([
SequenceIndices FirstInLongestSequence) ]) ] AddEndRangeIfNotThere [
AddStartRangeIfNotThere [: Primes [ RangeIndex ]
s=: 10 f 100
s
>./90 91 92 93 94 95 96 = s
s=: 1 f 2
>./s = 1
s=: 2 f 3
0 = $ s
s=: 8 f 9
>./s = 8 9
s=: 7 f 8
>./s = 8
s=: 10 f 11
>./s = 10
s=: 7 f 11
>./s = 8 9 10
s=: 200 f 300
s
>./0 = 1 p: s
1 = 1 p: _1 + 1 {. s
1 = 1 p: 1 + _1 {. s
s=: 2000 f 3000
s
>./0 = 1 p: s
1 = 1 p: _1 + 1 {. s
1 = 1 p: 1 + _1 {. s
On 2017-09-15 11:36, Skip Cave wrote:
Write a function f, which will list the longest set of consecutive
non-prime integers between two prime numbers in the interval x, y
for example:
10 f 100
90 91 92 93 94 95 96
Skip Cave
Cave Consulting LLC
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