Merge pull request #3432 from kaicb97/branch-for-challenge-097

perl solution for week 97

2 files changed, 131 insertions, 0 deletions

diff --git a/challenge-097/kai-burgdorf/perl/ch-1.pl b/challenge-097/kai-burgdorf/perl/ch-1.pl
new file mode 100755
index 0000000000..52dec58b8c
--- /dev/null
+++ b/challenge-097/kai-burgdorf/perl/ch-1.pl
@@ -0,0 +1,25 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+my $S = $ARGV[0] || "";
+my $N = $ARGV[1] || 0;
+
+$N = $N%26;
+
+my @chars = split //, $S;
+
+foreach(@chars) {
+
+    my $original_ascii = ord($_);
+    my $shifted_ascii = $original_ascii-$N;
+
+    if(($original_ascii < 91 && $shifted_ascii < 65) or ($original_ascii >= 97 && $shifted_ascii < 97)) {
+      $shifted_ascii += 26;
+    }
+
+    print chr($shifted_ascii);
+}
+
+print "\n";
diff --git a/challenge-097/kai-burgdorf/perl/ch-2.pl b/challenge-097/kai-burgdorf/perl/ch-2.pl
new file mode 100755
index 0000000000..f7efeadad9
--- /dev/null
+++ b/challenge-097/kai-burgdorf/perl/ch-2.pl
@@ -0,0 +1,106 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Algorithm::Permute;
+
+my $B = $ARGV[0] || "101100101";
+my $S = $ARGV[1] || 3;
+
+die "(length of $B) " . ( length $B ) . " % $S = " . ( ( length $B ) % $S ) . ", must be 0"
+  if ( ( length $B ) % $S != 0 );
+
+my @substrings   = get_sequences($B);
+my $permutations = get_permutations($S);
+my %result       = %{ get_number_of_flips( $permutations, \@substrings ) };
+
+print_output( $B, $S, \%result, \@substrings );
+
+sub get_number_of_flips {
+    my ( $p, $s ) = @_;
+
+    my @sequences = @$s;
+
+    my $shortest_distance;
+    my $shortest_target = $sequences[0];
+
+    while ( my @res = $p->next ) {
+        my $sum = 0;
+
+        foreach (@sequences) {
+            my $bits = join "", @res;
+            $sum += hemming_distance( $_, $bits );
+        }
+
+        if ( !$shortest_distance || $sum < $shortest_distance ) {
+            $shortest_distance = $sum;
+            $shortest_target   = join "", @res;
+        }
+    }
+
+    return { target => $shortest_target, flips => $shortest_distance };
+}
+
+sub get_sequences {
+    my ($b) = @_;
+
+    my @digits = split //, $b;
+
+    my @substrings;
+    while (@digits) {
+        my $sequence;
+        for ( my $i = 0 ; $i < $S ; $i++ ) {
+            $sequence .= shift @digits;
+        }
+        push @substrings, $sequence;
+    }
+
+    return @substrings;
+}
+
+sub get_permutations {
+    my ($number_of_digits) = @_;
+
+    my @tmp;
+    for ( 1 .. $number_of_digits ) {
+        push @tmp, 0;
+        push @tmp, 1;
+    }
+
+    return Algorithm::Permute->new( \@tmp, $number_of_digits );
+}
+
+sub hemming_distance {
+    my ( $first, $second ) = @_;
+
+    my @a = split "", $first;
+    my @b = split "", $second;
+
+    my $distance = 0;
+
+    my $i = 0;
+    foreach (@a) {
+        if ( $a[$i] ne $b[$i] ) {
+            $distance++;
+        }
+        $i++;
+    }
+
+    return $distance;
+}
+
+sub print_output {
+    my ( $b, $s, $result, $substrings ) = @_;
+
+    print "Input: \$B = $b, \$S = $s\nOutput: $result->{flips}\n\nBinary Substrings:\n";
+
+    @substrings = @$substrings;
+
+    foreach (@substrings) {
+        my $distance = hemming_distance( $_, $result->{target} );
+        print "\"$_\": $distance flip ";
+        print "to make it $result->{target}" if ( $distance > 0 );
+        print "\n";
+    }
+}