use bigint and chop arbitrarilly large numbers into words to be bitwi…

…se diffed.

challenge-059/jaredor/perl/ch-2.pl

@@ -2,28 +2,48 @@
 
 use v5.012;
 use warnings;
+use bigint;
 use Config;
-use List::Util qw(all sum);
+use List::Util qw(all sum max);
 
 # PWC 059, TASK #2 : Bit Sum
 
 # Answer based on perl doc for unpack and www.perlmonks.org/?node_id=407933
 
+my ( $LL, $NN ) =
+  defined $Config{longlongsize}
+  ? ( 8 * $Config{longlongsize}, 'Q' )
+  : ( 8 * $Config{longsize}, 'L' );
+
+my $CHOP_SIZE = 2**${LL};
+my $CHOP_ZERO = pack "${NN}", 0;
+
 die "This script requires one or more positive integer arguments."
   unless @ARGV;
 
 die "Not all arguments to the script are positive integers."
   unless all { /\A [1-9] \d* \Z/xms } @ARGV;
 
-my ( $LL, $NN ) =
-  defined $Config{longlongsize}
-  ? ( 8 * $Config{longlongsize}, 'Q' )
-  : ( 8 * $Config{longsize}, 'L' );
+#my @nums = map { pack "${NN}*", $_ } @ARGV;
+
+sub chop_up {
+    my ( $num, @chopped ) = ( 0 + $_[0], );
+    while ($num) {
+        push @chopped, $num % $CHOP_SIZE;
+        $num = int( $num / $CHOP_SIZE );
+    }
+    return [ map { pack "${NN}", $_ } @chopped ];
+}
 
-my @nums = map { pack "${NN}*", $_ } @ARGV;
+my @nums  = map     { chop_up $_ } @ARGV;
+my $chops = max map { $#$_ } @nums;
+( $chops - $#$_ ) and push @$_, ($CHOP_ZERO) x ( $chops - $#$_ ) for @nums;
 
-my ( @diffbits, $num );
-while ( $num = pop @nums ) {
-    push @diffbits, unpack( "%${LL}b*", $num ^ $_ ) for @nums;
+my ( @diffbits, $numa );
+while ( $numa = shift @nums ) {
+    for my $numb (@nums) {
+        push @diffbits, unpack( "%${LL}b*", $numa->[$_] ^ $numb->[$_] )
+          for 0 .. $chops;
+    }
 }
 say @diffbits ? sum @diffbits : 0;