Brackets and Bases solutions submitted

2 files changed, 98 insertions, 0 deletions

diff --git a/challenge-042/saiftynet/perl5/ch-1.pl b/challenge-042/saiftynet/perl5/ch-1.pl
new file mode 100644
index 0000000000..3a4e4bd343
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+++ b/challenge-042/saiftynet/perl5/ch-1.pl
@@ -0,0 +1,58 @@
+#!/usr/env perl
+# Perl Weekly Challenge 42-1 Script
+# Octal Number System Write a script to print decimal number 0 to 50
+# in Octal Number System.
+# Task extended to allow conversion into any base
+# from 2 to 36 (using A-Z), and also converts back from any base 
+# back to decimal
+
+use strict; use warnings;
+
+my $base=8;
+
+print "Converting from decimal to octal (base 8)\n";
+
+for my $n (1..50){
+  printf ("Decimal %2s is %2s in base %1s\n",$n, decimalTobaseN($base,$n), $base) ; 
+}
+
+sub decimalTobaseN{
+   my ($base,$number)=@_;                   # Function receives base and the number to convert
+   my @digits=(0..9,'A'..'Z');              # potential output characters
+
+   my $string="";                           # holds the output as string of characters
+   
+   while ($number>0){                       # continue until no more required
+      my $remainder=$number % $base;        # get the remainder after division with base
+      $string=$digits[$remainder].$string;  # add that to the left most side of string 
+      $number=($number-$remainder)/$base;   # divide the residual number by base
+   }
+   
+   return $string                           # return the result
+}
+
+# The following section describes a function inverse of decimalToBaseN()
+# Goal is to convert baseN string generated above back to decimal
+
+print "\n\nPress any key to continue\n";
+<STDIN>;
+print "Converting decimal 100 into bases 2 to 36 and then back again\n\n";
+
+for $base (2..36){                         # for each valid base
+	  my $a = decimalTobaseN($base,100);   # convert decimal 100 into that base
+	  my $b = baseNToDecimal($base,$a);    # then convert result back to decimal
+	  
+	  printf ("Decimal 100 in base %2s is %2s and converted back is %2s\n",$base, $a, $b) ; 
+}
+
+sub baseNToDecimal{
+   my ($base,$string)=@_;                   # Function receives base and the string to convert
+   my %baseValues;                          # the base characters to decimal value are 
+   @baseValues{(0..9,'A'..'Z')}=(0..36);    # stored in a hash 
+   my $result=0;                            # initial value is zero
+   foreach (split //,$string){              # go over each character in the string
+	                                        # multiplying result by the base before adding
+	   $result=$result*$base+$baseValues{$_};  # next character value to result
+   }
+   return $result;                          # return the result
+}
diff --git a/challenge-042/saiftynet/perl5/ch-2.pl b/challenge-042/saiftynet/perl5/ch-2.pl
new file mode 100644
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+++ b/challenge-042/saiftynet/perl5/ch-2.pl
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+#!/usr/env perl
+# Perl Weekly Challenge 42-2 Script
+# Write a script to generate a string with random number
+# of ( and ) brackets. Then make the script validate the
+# string if it has balanced brackets.
+
+# This gcontains two subroutines, 1 to generate random strings, 
+# (random in both length and sequence) and one to test whether
+# the brackets are balanced or not.  The script also shows which
+# are the unmtached brackets.
+#
+# With random strings, unblanaced strings are far more common
+# so 100 are generated and tested
+
+
+for (1..100){
+	my $testString=randomString();          # generate random string
+	printf ("  %-12s", $testString);        # display it
+	print  findError($testString),  "\n";   # validate it
+}
+
+sub randomString{                           
+	my $string="";                          # start with empty string
+	for (0..(rand()*5+1)){                  # for a random length (2 - 7)        
+		$string.=("(",")")[rand()*2];       # keep adding a random bracket
+	}
+	$string;                                # return the string
+}
+
+sub findError{
+	my $str=shift;
+	while ($str =~s/\((-*)\)/-\1-/){};      # keep replacing matched braces with
+	                                        # hyphens. What is left are string
+	                                        # contaning unmatched brackets
+	                                        # If these exist, they show locations
+	                                        # of errors
+	if ($str=~/\(|\)/){ return "Not ok unmatched brackets at $str "};
+	"OK, Balanced brackets";
+	
+}