Achilles numbers: Difference between revisions
→{{header|Perl}}: add a translation from Wren
SqrtNegInf (talk | contribs) (Added Perl) |
(→{{header|Perl}}: add a translation from Wren) |
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8 digits: 7395
9 digits: 24008</pre>
Here is a translation from Wren version 2, as an alternative.
<lang perl>use strict;
use warnings;
my %pps;
my $maxDigits = 9;
sub totient {
my $tot = my $n = shift;
my $i = 2;
while ($i*$i <= $n) {
unless ($n % $i) {
until($n % $i) { $n = int($n/$i) }
$tot -= int($tot/$i)
}
if ($i == 2) { $i = 1 }
$i += 2;
}
if ($n > 1) { $tot -= int($tot/$n) }
return $tot
}
sub getPerfectPowers {
for my $i (2..int(sqrt(my $upper = 10**( shift )))) {
my $p = $i;
while (($p *= $i) < $upper) { $pps{$p}++ }
}
}
sub getAchilles {
my ($lower, $upper) = map { 10** $_ } @_ ;
my %achilles = ();
my $count = 0;
for my $b (1..int($upper**(1/3))) {
my ($b3,$p) = $b * $b * $b;
for my $a (1..int(sqrt($upper))) {
last if (($p = $b3 * $a * $a) >= $upper);
$achilles{$p}++ if ($p >= $lower and !$pps{$p})
}
}
return keys %achilles
}
getPerfectPowers $maxDigits;
my @achilles = sort { $a <=> $b } getAchilles(1,5);
my %achillesSet;
@achillesSet{ @achilles } = undef;
print "First 50 Achilles numbers:\n";
for (0..49) { printf "%5d".($_%10 == 9 ? "\n" : " "), $achilles[$_] }
my %strongAchilles;
my $count = my $n = 0;
for (my $count = my $n = 0; $count < 30; $n++) {
if ( exists($achillesSet{ totient( $achilles[$n] ) })) {
$strongAchilles{ $achilles[$n] }++;
$count++
}
}
my @strongAchilles30 = (sort { $a <=> $b } keys %strongAchilles)[0..29];
print "\nFirst 30 strong Achilles numbers:\n";
for (0..29) { printf "%5d".($_%10 == 9 ? "\n" : " "), $strongAchilles30[$_] }
print "\nNumber of Achilles numbers with:\n";
for my $d (2..$maxDigits) {
printf "%2d digits: %d\n", $d, scalar getAchilles($d-1, $d)
}</lang>
Output is the same.
=={{header|Phix}}==
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