If u have horse instead of A1 
          lion instead of A2
          mule instead of A3
          tiger instead of A4

##</code><code>##

 
__DATA__
horse;tiger
lion;mule
lion;tiger
horse;mule

##</code><code>##

use strict;
use warnings;

my %A;
my ($max_row, $max_col) = (4,4);

# autovivify interesting rows/cols of %A
while (<DATA>) {
  warn("Line $.: cannot understand: $_") , next unless /(\w+);(\w+)/
+;
  my ($row, $col) = ($1,$2);
  $A{$row}{$col}++;
  $A{$col}{$row}++; # uncomment if relationship is not bidirectional
}

# print col. header
print "    ";
printf("%-3d",$_) for (1..$max_col);
print "\n";

#print matrix A
for my $row (1 .. $max_row) {
  printf("%-3d", $row);

  for my $col (1 .. $max_col) {
    printf(" %-3d",  exists $A{$row}{$col} ? "1" : "0" );
  }
  print "\n";
}


##</code><code>##

printing as 
    1  2  3  4  
1   0   0   0   0   
2   0   0   0   0    
3   0   0   0   0    
4   0   0   0   0     
 
##</code><code>##

  
      horse lion mule tiger
horse  0     0    1    1
lion   0     0    1    1
mule   1     1    0    0
tiger  1     1    0    0