wip better msgs before fix graph names

[appendix-a6.git] / parse

diff --git a/parse b/parse
index 8828deec85ee3542e80421a56ce13d2a3a034a6e..7ca1ed6aa70817165ca476ac6323a37f4404506e 100755 (executable)
--- a/parse
+++ b/parse
@@ -1,12 +1,14 @@
 #!/usr/bin/perl -w
 use strict;
 use utf8;
+use autodie;
 
 use Data::Printer;
+use Graph::Directed;
 
-binmode STDIN, 'encoding(UTF-8)' or die;
-binmode STDOUT, 'encoding(UTF-8)' or die;
-binmode STDERR, 'encoding(UTF-8)' or die;
+binmode STDIN, 'encoding(UTF-8)';
+binmode STDOUT, 'encoding(UTF-8)';
+binmode STDERR, 'encoding(UTF-8)';
 
 our @choices;
 our %choices;
@@ -49,7 +51,13 @@ if (!$defcho) {
 my $defi = $defcho->{Index};
 die "FD has smaj?!" if $defcho->{Smaj};
 
-our @vab; # $vab[$ia][$ib] = V(A,B)
+our @vab;
+# $vab[$ia][$ib] = V(A,B)
+# Actually, it's a list of voters who prefer A to B (A.6(3)(1))
+
+# Go through the voters and construct V(A,B)
+
+print "\nDefeats matrix\n";
 
 foreach my $iv (@invotes) {
     my ($votestr,$voter) = @$iv;
@@ -80,33 +88,34 @@ foreach my $iv (@invotes) {
 
 our @ch = map { $choices{$_} } @choices;
 
+# Print the counts V(A,B)
 foreach my $iy (-2..$#ch) {
     foreach my $ix (-2..$#ch) {
        if ($iy==-1) {
            if ($ix==-1) {
-               printf "+" or die;
+               printf "+";
            } else {
-               printf "------" or die;
+               printf "------";
            }
        } elsif ($ix==-1) {
-           printf "|" or die;
+           printf "|";
        } elsif ($ix==-2 && $iy==-2) {
-           printf "V(Y,X)" or die;
+           printf "V(Y,X)";
        } elsif ($iy==-2) {
-           printf "%5s ", $choices[$ix] or die $!;
+           printf "%5s ", $choices[$ix];
        } elsif ($ix==-2) {
-           printf "%5s ", $choices[$iy] or die $!;
+           printf "%5s ", $choices[$iy];
        } else {
            my $v = \( $vab[$iy][$ix] );
            $$v ||= [ ];
            if (@$$v) {
-               printf "%5d ", (scalar @$$v) or die $!;
+               printf "%5d ", (scalar @$$v);
            } else {
-               printf "%5s ", "" or die $!;
+               printf "%5s ", "";
            }
        }
     }
-    printf "\n" or die $!;
+    printf "\n";
 }
 
 sub drop ($$) {
@@ -115,7 +124,7 @@ sub drop ($$) {
     $ch[$i]{Dropped} = $why;
 }
 
-print "# quorum\n" or die;
+print "\nQuorum A.6(2) (quorum is $quorum)\n";
 
 foreach my $i (0..$#choices) {
     next if $ch[$i]{Dropped};
@@ -125,19 +134,120 @@ foreach my $i (0..$#choices) {
     drop $i, "quorum ($v < $quorum)";
 }
 
-print "# maj. ratio\n" or die;
+print "\nMajority ratio A.6(3)\n";
 
 foreach my $i (0..$#choices) {
     next if $ch[$i]{Dropped};
     next if $i == $defi;
     my $majr = $ch[$i]{Smaj};
-    $majr ||= [1,1];
+    $majr ||= [1,1]; # A.6(3)(3)
     my $vad = scalar @{ $vab[$i][$defi] };
     my $vda = scalar @{ $vab[$defi][$i] };
     next if $vad * $majr->[1] > $vda * $majr->[0];
     drop $i, "majority ratio ($vad * $majr->[1] <= $vda * $majr->[0])";
 }
 
+my $defeats = Graph::Directed->new; # A.6(4)
+
+sub chremain () {
+    return grep { !$ch[$_]{Dropped} } (0..$#ch);
+}
+
+foreach my $ia (chremain()) {
+    $defeats->add_vertex($ia);
+    foreach my $ib (chremain()) {
+       my $vab = scalar @{ $vab[$ia][$ib] };
+       my $vba = scalar @{ $vab[$ib][$ia] };
+       next unless $vab > $vba;
+       print "defeat: $choices[$ia] beats $choices[$ib] ($vab > $vba)\n";
+       $defeats->add_vertex($ia,$ib);
+    }
+}
+
+sub weaker ($$) {
+    # A.6(7)(1)
+    my ($def1,$def2) = @_;
+    my ($ia,$ix) = @$def1;
+    my ($ib,$iy) = @$def1;
+    return 1 if $vab[$ia][$ix] < $vab[$ib][$iy];
+    return 1 if $vab[$ia][$ix] == $vab[$ib][$iy]
+       && $vab[$ix][$ia] > $vab[$iy][$ib];
+    return 0;
+}
+
+our $schwartz;
+
+for (;;) {
+    # loop from A6(5)
+
+    print "defeats graph: $defeats\n";
+
+    print "\nTransitive closure A.6(5)\n";
+
+    my $tdefeats = $defeats->transitive_closure();
+
+    print "closure graph: $tdefeats\n";
+
+    print "\nSchwartz set A.6(6)\n";
+    
+    $schwartz = $defeats->copy();
+
+    foreach my $ia (chremain()) {
+       foreach my $ib (chremain()) {
+           next if $tdefeats->has_edge($ia,$ib);
+           next if !$tdefeats->has_edge($ib,$ia);
+           print "not in Schwartz set: $choices[$ia] because $choices[$ib]\n";
+           $schwartz->delete_vertex($ia);
+           last;
+       }
+    }
+
+    print "\nDropping weakest defeats A.6(7)\n";
+
+    our @weakest = ();
+
+    foreach my $edge ($schwartz->edges()) {
+       if (!@weakest) {
+           # no weakest edges yet
+       } elsif (weaker($edge, $weakest[0])) {
+           # this edge is weaker than previous weakest, start new set
+           @weakest = ();
+       } elsif (weaker($weakest[0], $edge)) {
+           # weakest edge is weaker than this one, ignore this one
+           next;
+       } else {
+           # weakest edge is exactly as weak as this one, add this one
+       }
+       push @weakest, $edge;
+    }
+
+    last unless @weakest;
+    
+    printf "weakest defeats %d > %d", 
+       (scalar @{ $vab[$_->[0]][$_->[1]] }),
+       (scalar @{ $vab[$_->[1]][$_->[0]] });
+    foreach my $weakest (@weakest) {
+       my ($ia,$ib) = @$weakest;
+       print "weakest defeat $choices[$ia] > $choices[$ib]\n";
+       $defeats->delete_edge($ia,$ib);
+    }
+
+    print "defeats within the Schwartz set, round again\n";
+}
+
+print "no defeats within the Schwartz set\n";
+print "final schwartz set:\n\n";
+
+if ($schwartz->vertices() == 1) {
+    print "WINNER IS:\n";
+} else {
+    print "WINNER IS ONE OF (CASTING VOTE DECIDES):\n";
+}
+
+printf "    %-5s %s\n", $choices[$_], $ch[$_]{Desc}
+    foreach ($schwartz->vertices());
+
+print ".\n";
 
 #p %choices;
 #p @vab;