Successive prime differences: Difference between revisions
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Thundergnat (talk | contribs) (→{{header|Perl 6}}: Add a Perl 6 example) |
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<br>Note: Generation of a list of primes is a secondary aspect of the task. Use of a built in function, well known library, or importing/use of prime generators from other [[Sieve of Eratosthenes|Rosetta Code tasks]] is encouraged. |
<br>Note: Generation of a list of primes is a secondary aspect of the task. Use of a built in function, well known library, or importing/use of prime generators from other [[Sieve of Eratosthenes|Rosetta Code tasks]] is encouraged. |
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=={{header|Perl 6}}== |
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{{works with|Rakudo|2019.03}} |
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Essentially the code from the [[Sexy_primes#Perl6|Sexy primes]] task with minor tweaks. |
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<lang perl6>use Math::Primesieve; |
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my $sieve = Math::Primesieve.new; |
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my $max = 1_000_000; |
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my @primes = $sieve.primes($max); |
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my $filter = @primes.Set; |
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my $primes = @primes.categorize: { .&succesive } |
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sub succesive ($i) { |
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gather { |
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take '2' if $filter{$i + 2}; |
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take '1' if $filter{$i + 1}; |
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take '2_2' if all($filter{$i «+« (2,4)}); |
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take '2_4' if all($filter{$i «+« (2,6)}); |
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take '4_2' if all($filter{$i «+« (4,6)}); |
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take '6_4_2' if all($filter{$i «+« (6,10,12)}); |
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} |
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} |
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sub comma { $^i.flip.comb(3).join(',').flip } |
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for (2,), (1,), (2,2), (2,4), (4,2), (6,4,2) -> $succ { |
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say "## Sets of {1+$succ} successive primes <= { comma $max } with " ~ |
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"successive differences of {$succ.join: ', ' }"; |
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my $i = $succ.join: '_'; |
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for 'First', 0, ' Last', * - 1 -> $where, $ind { |
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say "$where group: ", join ', ', [\+] flat $primes{$i}[$ind], |$succ |
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} |
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say ' Count: ', +$primes{$i}, "\n"; |
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}</lang> |
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{{out}} |
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<pre>## Sets of 2 successive primes <= 1,000,000 with successive differences of 2 |
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First group: 3, 5 |
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Last group: 999959, 999961 |
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Count: 8169 |
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## Sets of 2 successive primes <= 1,000,000 with successive differences of 1 |
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First group: 2, 3 |
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Last group: 2, 3 |
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Count: 1 |
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## Sets of 3 successive primes <= 1,000,000 with successive differences of 2, 2 |
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First group: 3, 5, 7 |
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Last group: 3, 5, 7 |
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Count: 1 |
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## Sets of 3 successive primes <= 1,000,000 with successive differences of 2, 4 |
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First group: 5, 7, 11 |
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Last group: 999431, 999433, 999437 |
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Count: 1393 |
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## Sets of 3 successive primes <= 1,000,000 with successive differences of 4, 2 |
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First group: 7, 11, 13 |
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Last group: 997807, 997811, 997813 |
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Count: 1444 |
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## Sets of 4 successive primes <= 1,000,000 with successive differences of 6, 4, 2 |
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First group: 7, 13, 17, 19 |
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Last group: 997141, 997147, 997151, 997153 |
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Count: 337 |
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</pre> |
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=={{header|Python}}== |
=={{header|Python}}== |
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