Box
           Response  1          2        3
Red/Green  yes/no    Red/Green  Red/Red  Green/Red
           no/yes    Red/Green  Red/Red  Green/Red
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use strict;
use warnings;

use constant { LEFT => 0, RIGHT => 1 };

sub prepare {
        my( $tree, $w, $lr, $level, $col, $canvas, $chars ) = @_;
        if( ref($tree) ) {
                my( $lcol, $rcol ) = map { 
                        $$col += $w*$_; 
                        prepare( $tree->[$_], $w, $_, $level+1, $col, 
+$canvas, $chars ) 
                } LEFT, RIGHT;
                $canvas->[$level  ]->[$lcol] = $$chars[LEFT];
                $canvas->[$level-1]->[$_   ] = '_' for $lcol+1..$rcol-
+1;
                $canvas->[$level  ]->[$rcol] = $$chars[RIGHT];    
                return $lr ? $lcol : $rcol;
        } else {
                $canvas->[$level++]->[$$col] = $_ for split //, $tree;
+      
                return $$col;
        }
}

sub dumpTree {
        my ($col, @canvas ) = (1);
        my $width = $_[1] > 0 ? 1+$_[1] : 1;
        my $chars = $_[2] ? [ '|', '|' ] : [ '/', '\\' ];
        prepare( $_[0], $width, RIGHT, 1, \$col, \@canvas, $chars );
        return join( '', map { join( '', map { $_ // ' ' } @$_, "\n" )
+ } @canvas );
}

sub randomTree {
        my @t = @_;
        my $r;
        $r = int( rand $#t ), splice @t, $r, 2, [ @t[ $r, $r+1 ]] whil
+e @t > 1;
        return $t[0];
}

my @t1 = ( 'a'..'z' );
my @t2 = qw( Alpha Beta Gamma Delta Epsilon Zeta Eta Theta Iota Kappa 
+Lambda
             Mu Nu Xi Omicron Pi Rho Sigma Tau Upsilon Phi Chi Psi Ome
+ga);

print dumpTree( randomTree( @t1 ), 1 );
print dumpTree( randomTree( @t2 ), 3, 1 );
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