in reply to Reconstructing List Order From Partial Subsets
Using liverpole's hash idea, I've come up with this (updated with comments):
use strict; use warnings; my (%pos, @order); # collect the position information { local $/ = ""; while (<DATA>) { chomp; my $i = 0; # $pos{TERM}{SET #} = POSITION $pos{$_}{$. - 1} = $i++ for split /\n/; } } # extract order from the positions for my $i (1 .. keys %pos) { # get all terms who appear ONLY in position 0 # across all the sets they're in my ($first, @extra) = grep { my $t = $_; my %p = map { $_ => 1 } values %{ $pos{$t} }; $p{0} and keys(%p) == 1 } keys %pos; # if there was more than one term found, cause a fuss warn "iteration #$i: multiple candidates [$first @extra]\n" if @extr +a; # uncomment for debugging to see how %pos changes # use Data::Dumper; print Dumper(\%pos); # get the sets this term appeared in and alter # the positions of terms found in those sets for my $set (keys %{ delete $pos{$first} }) { $pos{$_}{$set} and $pos{$_}{$set}-- for keys %pos; } # store this term in the ordered list push @order, $first; } print "<@order>\n"; __DATA__ alpha beta epsilon zeta beta gamma zeta alpha gamma delta epsilon
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Re^2: Reconstructing List Order From Partial Subsets
by jdporter (Paladin) on Jul 26, 2006 at 17:00 UTC | |
by japhy (Canon) on Jul 26, 2006 at 17:14 UTC | |
by QM (Parson) on Jul 26, 2006 at 18:11 UTC | |
by QM (Parson) on Aug 01, 2006 at 22:03 UTC | |
by jdporter (Paladin) on Aug 02, 2006 at 14:01 UTC | |
by QM (Parson) on Aug 02, 2006 at 20:37 UTC |
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