compute: handle >9 candidates properly

[appendix-a6.git] / stv

diff --git a/stv b/stv
index ba89fce1bfd4dcd359d86f80fe0555820db25cd8..68940f452683825259efcecc5fdc2fffbb7c3a38 100755 (executable)
--- a/stv
+++ b/stv
@@ -20,6 +20,25 @@ use List::MoreUtils qw(nsort_by);
 our $stage=0;
 our @allvotes;
 
 our $stage=0;
 our @allvotes;
 

+our %tiebreak; # $tiebreak{ winningcand }{ losingcand } = 1
+
+while (@ARGV && $ARGV[0] =~ m/[<>]/) {
+    my ($losers, $winners) = ($? eq '<' ? ($`, $') : ($', $`));
+    my @losers = sort split /\,/, $losers;
+    my @winners = sort split /\,/, $winners;
+    die "@losers @winners" if @losers>1 && @winners>1;
+    my @all = sort @losers, @winners;
+    my $record = sub {
+       my ($how, $howers) = @_;
+       return unless @$howers == 1;
+       die "@all $how" if defined $tiebreak{$how}{"@all"};
+       $tiebreak{$how}{"@all"} = $howers->[0];
+    };
+    $record->('winner', \@winners);
+    $record->('loser',  \@losers);
+    shift @ARGV;
+}    
+

 our $places = shift @ARGV;
 die unless $places eq ($places + 0);
 
 our $places = shift @ARGV;
 die unless $places eq ($places + 0);
 


@@ -95,27 +114,56 @@ sub equalpiles ($@) {
 
 sub historically_prefer ($@) {
     my ($signum, @choices) = @_;
 
 sub historically_prefer ($@) {
     my ($signum, @choices) = @_;

+    # $signum==+1 means choose candidates with more early preferences

 
     return $choices[0] if @choices < 2;
 
     my $compare = sub {
        foreach my $sr (@stagerecord) {
 
     return $choices[0] if @choices < 2;
 
     my $compare = sub {
        foreach my $sr (@stagerecord) {

-           my $d = $sr->{ $a->{Cand} } <=> $sr->{ $b->{Cand} };
-           return $d * $signum if $d;
+           my $d = ($sr->{ $a->{Cand} }//0) <=> ($sr->{ $b->{Cand} }//0);
+           return -$d * $signum if $d;

        }
        return 0;
     };
 
        }
        return 0;
     };
 

-    @choices = sort $compare, @choices;
+    @choices = sort $compare @choices;
+
+    print DEBUG "historically_prefer\n",
+       Data::Dumper->Dump([\@choices, \@stagerecord],
+                          [qw(_@choices _@stagerecord)]);
+
+    foreach my $s (@choices) {
+       my $c = $s->{Cand};
+       printf " %6s %10s |", 'tiebrk', $c;
+       foreach my $sr (@stagerecord) {
+           my $p = pr($sr->{$c} // 0);
+           $p =~ s/\.0+\b//g;
+           $p =~ s/ //g;
+           print "$p|";
+       }
+       print "\n";
+    }
+

     $a = $choices[0];
     $a = $choices[0];

-    my $numequal = 0;
+    my $numequal = 1;

     for (;;) {
     for (;;) {

-       last unless $numequal >= @choices;
+       last if $numequal >= @choices;

        $b = $choices[$numequal];
        last if $compare->();
        $b = $choices[$numequal];
        last if $compare->();

+       $numequal++;
+    }
+
+    if ($numequal > 1) {
+       my $how = $signum > 0 ? 'winner' : 'loser';
+        my @all = sort map { $_->{Cand} } @choices[ 0 .. $numequal-1 ];
+       my $hower = $tiebreak{$how}{"@all"};
+       if (defined $hower) {
+           printf "%7.7s %10s !!!!!!!!!!\n", "TIE".(uc $how), $hower;
+           return grep { $_->{Cand} eq $hower } @choices;
+       }
+       die "need tie break for $how between @all\n";

     }
 
     }
 

-    die 'random choice unimplemented' if $numequal > 1;

     return $choices[0];
 }
 
     return $choices[0];
 }
 


@@ -160,7 +208,7 @@ for (;;) {
     }
     my @sorted;
     my $things_update = sub {
     }
     my @sorted;
     my $things_update = sub {

-       foreach my $s (@surpluses, values %sorted) {
+       foreach my $s (values %sorted) {

            $s->{Total} = sum0 map { $_->{Weight} } @{ $s->{Votes } };
        }
        @sorted = nsort_by { -$_->{Total} } values %sorted;
            $s->{Total} = sum0 map { $_->{Weight} } @{ $s->{Votes } };
        }
        @sorted = nsort_by { -$_->{Total} } values %sorted;


@@ -203,19 +251,31 @@ for (;;) {
        my $s = $sorted[0];
        my $topvoters = $s->{Total};
        my $surplus = $topvoters - $quota;
        my $s = $sorted[0];
        my $topvoters = $s->{Total};
        my $surplus = $topvoters - $quota;

-       last unless $surplus > 0;
+       last unless $surplus >= 0;
+       last unless $placesremain;

 
 

-       printf "%7s %10s ***************\n", 'ELECTED', $s->{Cand};
-       push @elected, $s->{Cand};
+       my @elect = equalpiles 'elect?', @sorted;

 
 

-       foreach my $vote (@{ $s->{Votes} }) {
-           votelog $vote, "elected $s->{Cand}";
+       if (@elect > $placesremain) {
+           # oh my god
+           @elect = historically_prefer +1, @elect;
+           printf "%7s %10s\n", 'tie!', $elect[0]{Cand};

        }
 
        }
 

-       $s->{Surplus} = $surplus;
-       push @newsurpluses, $s;
-       delete $sorted{ $s->{Cand} };
-       delete $continuing{ $s->{Cand} };
+       foreach $s (@elect) {
+           printf "%7s %10s ***************\n", 'ELECTED', $s->{Cand};
+           push @elected, $s->{Cand};
+
+           foreach my $vote (@{ $s->{Votes} }) {
+               votelog $vote, "elected $s->{Cand}";
+           }
+
+           $s->{Surplus} = $surplus;
+           push @newsurpluses, $s;
+           delete $sorted{ $s->{Cand} };
+           delete $continuing{ $s->{Cand} };
+           $placesremain--;
+       }

 
        $things_update->();
     }
 
        $things_update->();
     }


@@ -234,15 +294,18 @@ for (;;) {
            grep { !!voteliveprefs $_ }
            @$votes;
 
            grep { !!voteliveprefs $_ }
            @$votes;
 

+       my $derate = 1/1;

        printf "%7s %10s %s\n", 'xfrable', $s->{Cand}, pr $transferrable;
        if ($transferrable > $surplus) {
        printf "%7s %10s %s\n", 'xfrable', $s->{Cand}, pr $transferrable;
        if ($transferrable > $surplus) {

-           my $derate = $transferrable / $surplus;
+           $derate = $transferrable / $surplus;

            printf "%7s %10s %s\n", 'derate', $s->{Cand}, pr $derate;
            foreach my $vote (@{ $s->{Votes} }) {
                votelog $vote, "part of surplus, derated ". pr $derate;
                $vote->{Weight} /= $derate;
            }
        }
            printf "%7s %10s %s\n", 'derate', $s->{Cand}, pr $derate;
            foreach my $vote (@{ $s->{Votes} }) {
                votelog $vote, "part of surplus, derated ". pr $derate;
                $vote->{Weight} /= $derate;
            }
        }

+       $s->{Total} = $transferrable / $derate;
+

        push @surpluses, $s;
 
        $things_update->();
        push @surpluses, $s;
 
        $things_update->();