13 lines
296 B
Perl
13 lines
296 B
Perl
sub isprime {
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my $n = shift;
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return ($n >= 2) if $n < 4;
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return unless $n % 2 && $n % 3;
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my $sqrtn = int(sqrt($n));
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for (my $i = 5; $i <= $sqrtn; $i += 6) {
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return unless $n % $i && $n % ($i+2);
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}
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1;
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}
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my $s = 0;
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$s += !!isprime($_) for 1..100000;
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print "Pi(100,000) = $s\n";
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