Merge pull request #1164 from saiftynet/branch-044

Blending Numbers and operations together

2 files changed, 112 insertions, 0 deletions

diff --git a/challenge-044/saiftynet/perl/ch-1.pl b/challenge-044/saiftynet/perl/ch-1.pl
new file mode 100644
index 0000000000..7512fdfd77
--- /dev/null
+++ b/challenge-044/saiftynet/perl/ch-1.pl
@@ -0,0 +1,48 @@
+#!/usr/env perl
+# Perl Weekly Challenge             Challenge 044 Task 1
+# You are given a string “123456789”. Write a script that would
+# insert ”+” or ”-” in between digits so that when you evaluate,
+# the result should be 100.
+#
+# This soloution extends to allow any start string and any target#
+# anf prints all possible answers
+
+use strict; use warnings;
+
+tryInsert("123456789",100); # main call: provide intial string and target.
+
+# This subroutine splits a string into two at each possible position
+# in the string, and tries a calulation with a + or a - in beteen.
+# It then does the same with the second half of the string.
+# at each insert it evaluates the result, and prints the string
+# as a possible solution;  All discovered answers are displayed.
+
+sub tryInsert{
+	my ($str,$target,$marker)=@_;
+	$marker //=1;	      # $marker identifies the first insertion point
+	                      # further attempts ar from this point to the
+	                      # postion before the last character in the string 
+	foreach my $pos ($marker..((length $str)-1)){
+		foreach my $operator(qw{+ -}){
+		  my $temp=$str;                      # put in a temporary string
+		  substr $temp,$pos,0,$operator;      # insert the operator
+		  print $temp."\n"                    # print the reulting string
+		     if   eval ("$temp")==$target;    # only if the result is our $target 
+		  tryInsert($temp,$target,$pos+2);    # recurse with new insertion point 
+	    }
+	}
+}
+
+
+##     Output
+# 1+2+3-4+5+6+78+9
+# 1+2+34-5+67-8+9
+# 1+23-4+5+6+78-9
+# 1+23-4+56+7+8+9
+# 12+3+4+5-6-7+89
+# 12+3-4+5+67+8+9
+# 12-3-4+5-6+7+89
+# 123+4-5+67-89
+# 123+45-67+8-9
+# 123-4-5-6-7+8-9
+# 123-45-67+89
diff --git a/challenge-044/saiftynet/perl/ch-2.pl b/challenge-044/saiftynet/perl/ch-2.pl
new file mode 100644
index 0000000000..41f8c2bf30
--- /dev/null
+++ b/challenge-044/saiftynet/perl/ch-2.pl
@@ -0,0 +1,64 @@
+#!/usr/env perl
+# Perl Weekly Challenge             Challenge 044 Task 2
+# You have only $1 left at the start of the week. You have been given an
+# opportunity to make it $200. The rule is simple with every move you
+# can either double what you have or add another $1. Write a script to
+# help you get $200 with the smallest number of moves.
+#
+# This soloution extends to allow any start and any target
+
+use strict; use warnings;
+
+doubleOrAdd(1,200);     # The main call: Give a start and the target,   
+                        # returns the results to console
+
+sub doubleOrAdd{        # this routine takes starting value and final target
+  my ($start,$target)=@_;
+  
+  return print "Number out of bounds\n"         # too big takes too long and
+         if $target>100000 or $target<$start;   # can't be smaller than $target
+  
+  my @options=("$start");                       # initialise list of operations,
+  my $found=($start==$target);                  # do we already have goal?
+  
+  while (! $found){
+	  @options = map {("($_+1)","($_*2)")} @options; # add the two possible ops
+	  foreach  my $answer ( @options ) {      # test each of the sequences
+		if ( eval("$answer")==$target) {      # against our target
+			                            
+			# if found, announce it                               
+			# the answer will look like  (((((((((1+1)+1)*2)*2)*2)+1)*2)*2)*2)
+			# to make it easier to read, we will translate it to English
+			                         
+			# number of moves is count of open brackets,remove these.			                               
+			print $answer=~s/\(//g," moves required\n"; 
+			
+			$answer=~s/^(\d+)/Start with \$$1,\n/;   # the starting number is 1st number
+			$answer=~s/\+1\)/ add 1,\n/g;            # make the result human
+			$answer=~s/\*2\)/ double it,\n/g;        # readable:
+			
+			print $answer;
+			
+			
+			$found=1;last;                           # stop looking
+		};
+      };
+    }
+    print " Now you have \$$target!";                # declare discovery
+}
+
+##     Output
+# 9 moves required
+# Start with $1,
+#  add 1,
+#  add 1,
+#  double it,
+#  double it,
+#  double it,
+#  add 1,
+#  double it,
+#  double it,
+#  double it,
+#  gives you $200
+
+