Knuth's power tree: Difference between revisions
Rename Perl 6 -> Raku, alphabetize, minor clean-up
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Thundergnat (talk | contribs) (Rename Perl 6 -> Raku, alphabetize, minor clean-up) |
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Line 450:
191: [1, 2, 4, 8, 16, 32, 64, 128, 160, 176, 184, 188, 190, 191]
3 ^ 191 = 13494588674281093803728157396523884917402502294030101914066705367021922008906273586058258347</pre>
=={{header|Haskell}}==
Line 1,128 ⟶ 1,125:
191: (1 2 4 8 16 32 64 128 160 176 184 188 190 191)
3^191 = 13494588674281093803728157396523884917402502294030101914066705367021922008906273586058258347
</pre>
Line 1,403 ⟶ 1,348:
81: (1 2 3 5 10 20 40 41 81)
1.1^81 = 2253.2402360440283</pre>
=={{header|Raku}}==
(formerly Perl 6)
Paths are random. It is possible replace <code>.pick(*)</code> with <code>.reverse</code> if you want paths as in Perl, or remove it for Python paths.
<lang perl6>use v6;
sub power-path ($n ) {
state @unused_nodes = (2,);
state @power-tree = (False,0,1);
until @power-tree[$n].defined {
my $node = @unused_nodes.shift;
for $node X+ power-path($node).pick(*) {
next if @power-tree[$_].defined;
@unused_nodes.push($_);
@power-tree[$_]= $node;
}
}
( $n, { @power-tree[$_] } ...^ 0 ).reverse;
}
multi power ( $, 0 ) { 1 };
multi power ( $n, $exponent ) {
state %p;
my %r = %p{$n} // ( 0 => 1, 1 => $n ) ;
for power-path( $exponent ).rotor( 2 => -1 ) -> ( $p, $c ) {
%r{ $c } = %r{ $p } * %r{ $c - $p }
}
%p{$n} := %r ;
%r{ $exponent }
}
say 'Power paths: ', pairs map *.&power-path, ^18;
say '2 ** key = value: ', pairs map { 2.&power($_) }, ^18;
say 'Path for 191: ', power-path 191;
say '3 ** 191 = ', power 3, 191;
say 'Path for 81: ', power-path 81;
say '1.1 ** 81 = ', power 1.1, 81;
</lang>
{{out}}
<pre>
Power paths: (0 => () 1 => (1) 2 => (1 2) 3 => (1 2 3) 4 => (1 2 4) 5 => (1 2 3 5) 6 => (1 2 3 6) 7 => (1 2 3 6 7) 8 => (1 2 4 8) 9 => (1 2 3 6 9) 10 => (1 2 3 5 10) 11 => (1 2 3 6 9 11) 12 => (1 2 3 6 12) 13 => (1 2 3 6 12 13) 14 => (1 2 3 6 12 14) 15 => (1 2 3 6 9 15) 16 => (1 2 4 8 16) 17 => (1 2 4 8 16 17))
2 ** key = value: (0 => 1 1 => 2 2 => 4 3 => 8 4 => 16 5 => 32 6 => 64 7 => 128 8 => 256 9 => 512 10 => 1024 11 => 2048 12 => 4096 13 => 8192 14 => 16384 15 => 32768 16 => 65536 17 => 131072)
Path for 191: (1 2 3 6 9 18 27 54 108 162 189 191)
3 ** 191 = 13494588674281093803728157396523884917402502294030101914066705367021922008906273586058258347
Path for 81: (1 2 3 6 9 18 27 54 81)
1.1 ** 81 = 2253.24023604401
</pre>
=={{header|REXX}}==
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