Successive prime differences: Difference between revisions
Rename Perl 6 -> Raku, alphabetize, minor clean-up
Catskill549 (talk | contribs) |
Thundergnat (talk | contribs) (Rename Perl 6 -> Raku, alphabetize, minor clean-up) |
||
Line 30:
:#https://www.primepuzzles.net/puzzles/puzz_011.htm
:#https://matheplanet.de/matheplanet/nuke/html/viewtopic.php?topic=232720&start=0
=={{header|AWK}}==
<lang AWK>
Line 91 ⟶ 92:
112 1 370261,370373 370261,370373
</pre>
=={{header|C sharp}}==
<lang csharp>using System;
Line 674 ⟶ 676:
{{out}}
<pre> (2) has 8169 sets: 3 5 … 999959 999961
(1) has 1 sets: 2 3 … 2 3
(2 2) has 1 sets: 3 5 7 … 3 5 7
Line 879 ⟶ 784:
Last group: 997141, 997147, 997151, 997153
Count: 306</pre>
=={{header|Raku}}==
(formerly Perl 6)
===Categorized by Successive===
{{works with|Rakudo|2019.03}}
Essentially the code from the [[Sexy_primes#Perl_6|Sexy primes]] task with minor tweaks.
<lang perl6>use Math::Primesieve;
my $sieve = Math::Primesieve.new;
my $max = 1_000_000;
my @primes = $sieve.primes($max);
my $filter = @primes.Set;
my $primes = @primes.categorize: &successive;
sub successive ($i) {
gather {
take '2' if $filter{$i + 2};
take '1' if $filter{$i + 1};
take '2_2' if all($filter{$i «+« (2,4)});
take '2_4' if all($filter{$i «+« (2,6)});
take '4_2' if all($filter{$i «+« (4,6)});
take '6_4_2' if all($filter{$i «+« (6,10,12)}) and
none($filter{$i «+« (2,4,8)});
}
}
sub comma { $^i.flip.comb(3).join(',').flip }
for (2,), (1,), (2,2), (2,4), (4,2), (6,4,2) -> $succ {
say "## Sets of {1+$succ} successive primes <= { comma $max } with " ~
"successive differences of { $succ.join: ', ' }";
my $i = $succ.join: '_';
for 'First', 0, ' Last', * - 1 -> $where, $ind {
say "$where group: ", join ', ', [\+] flat $primes{$i}[$ind], |$succ
}
say ' Count: ', +$primes{$i}, "\n";
}</lang>
{{out}}
<pre>## Sets of 2 successive primes <= 1,000,000 with successive differences of 2
First group: 3, 5
Last group: 999959, 999961
Count: 8169
## Sets of 2 successive primes <= 1,000,000 with successive differences of 1
First group: 2, 3
Last group: 2, 3
Count: 1
## Sets of 3 successive primes <= 1,000,000 with successive differences of 2, 2
First group: 3, 5, 7
Last group: 3, 5, 7
Count: 1
## Sets of 3 successive primes <= 1,000,000 with successive differences of 2, 4
First group: 5, 7, 11
Last group: 999431, 999433, 999437
Count: 1393
## Sets of 3 successive primes <= 1,000,000 with successive differences of 4, 2
First group: 7, 11, 13
Last group: 997807, 997811, 997813
Count: 1444
## Sets of 4 successive primes <= 1,000,000 with successive differences of 6, 4, 2
First group: 31, 37, 41, 43
Last group: 997141, 997147, 997151, 997153
Count: 306
</pre>
===Precomputed Differences===
{{works with|Rakudo|2019.03}}
<lang perl6>use Math::Primesieve;
constant $max = 1_000_000;
constant @primes = Math::Primesieve.primes($max);
constant @diffs = @primes.skip Z- @primes;
say "Given all ordered primes <= $max, sets with successive differences of:";
for (2,), (1,), (2,2), (2,4), (4,2), (6,4,2) -> @succ {
my $size = @succ.elems;
my @group_start_offsets = @diffs.rotor( $size => 1-$size )
.grep(:k, { $_ eqv @succ });
my ($first, $last) = @group_start_offsets[0, *-1]
.map: { @primes.skip($_).head($size + 1) };
say sprintf '%10s has %5d sets: %15s … %s',
@succ.gist, @group_start_offsets.elems, $first, $last;
}</lang>
{{Out}}
<pre>Given all ordered primes <= 1000000, sets with successive differences of:
(2) has 8169 sets: 3 5 … 999959 999961
(1) has 1 sets: 2 3 … 2 3
(2 2) has 1 sets: 3 5 7 … 3 5 7
(2 4) has 1393 sets: 5 7 11 … 999431 999433 999437
(4 2) has 1444 sets: 7 11 13 … 997807 997811 997813
(6 4 2) has 306 sets: 31 37 41 43 … 997141 997147 997151 997153</pre>
=={{header|REXX}}==
Line 957 ⟶ 960:
count: 306
</pre>
=={{header|Ruby}}==
<lang ruby>require 'prime'
Line 977 ⟶ 981:
[6, 4, 2] has 306 sets. [31, 37, 41, 43]...[997141, 997147, 997151, 997153]
</pre>
=={{header|Scala}}==
<lang scala>object SuccessivePrimeDiffs {
| |||