- Added solutions by Kevin Colyer.

2 files changed, 130 insertions, 0 deletions

diff --git a/challenge-044/kevin-colyer/raku/ch-1.p6 b/challenge-044/kevin-colyer/raku/ch-1.p6
new file mode 100644
index 0000000000..c9abc9ee71
--- /dev/null
+++ b/challenge-044/kevin-colyer/raku/ch-1.p6
@@ -0,0 +1,74 @@
+#!/usr/bin/perl6
+use v6;
+
+use Test;
+
+
+=begin pod
+
+Task 1
+
+Only 100, please.
+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.
+
+=end pod
+
+sub MAIN(Str $number="123456789", Int :$target=100, Bool :$verbose=False, Bool :$all=False){
+    # try base 8 digits of base 3
+    # 0=nothing
+    # 1=+
+    # 2=-
+    my Int $bal = 1;
+    my $solution="";
+    my $bits=($number.chars-1); # possible permutations
+    my $fail=True;
+
+    # EVAL was too slow so let's use an accumulator and operand to avoid it.
+    for 3..^(3**$bits) -> Int $i {
+        # accumulator
+        my Int $acc=0;
+        # initial
+        my $operand =$number.substr(0,1); # Prime with first digit
+        # operator is +1 for add or -1 for subtract
+        my Int $operator = 1; # we start off adding the operand to 0 so set to +1
+
+        my Int $j=$i;
+        my @sum = $number.comb;
+
+        # for visualisation of answer
+        my Str $solution="1";
+        # compose the sum
+        for 1..$bits -> $index {
+            my $k = $j % 3;
+            if $k== 0 {
+                $operand ~=@sum[$index];
+                $solution~=@sum[$index];
+            } elsif $k==1 {
+                $acc=$acc+($operand*$operator);
+                $operator = 1;
+                $operand=@sum[$index];
+                $solution~="+" ~ @sum[$index];
+            } elsif $k==2 {
+                $acc=$acc+($operand*$operator);
+                $operator = -1;
+                $operand=@sum[$index];
+                $solution~="-" ~ @sum[$index];
+            }
+
+            $j=$j div 3;
+        }
+        # flush remaining ops
+        $acc=$acc+($operand*$operator);
+        # Answer is in the accumulator
+        # visual answer is in $solution
+        say "$i) checking $solution = "~ $acc if $verbose && $i %% 100;
+        if $target == $acc {
+            say "$number -> $solution = {$target} (Checked $i of {3**$bits-3} potential solutions)";
+            $fail=False;
+            exit unless $all;
+        }
+    }
+
+    say "No solution found for $number targeting $target" if $fail;
+
+}
diff --git a/challenge-044/kevin-colyer/raku/ch-2.p6 b/challenge-044/kevin-colyer/raku/ch-2.p6
new file mode 100644
index 0000000000..cdae78dd23
--- /dev/null
+++ b/challenge-044/kevin-colyer/raku/ch-2.p6
@@ -0,0 +1,56 @@
+#!/usr/bin/perl6
+use v6;
+
+use Test;
+
+
+=begin pod
+
+Task 2
+
+Make it $200
+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.
+
+=end pod
+
+
+# A simple example shows there are about 10 operations I can see. A best solution must be less than this.
+# 200 100 50 25 24 12 6 3 1 1
+# if I take 10 bits in base two, a 1 is add and a 0 is double.
+# Count up to 2**10 and see if == 200, if better keep solution
+
+
+constant TARGET = 200;
+my Int $bal = 1;
+my $bestSolution="";
+my $bestSolutionMoves=TARGET; # about as infinite as we need
+my $bits=TARGET/10; # just a guess
+for ^2**10 -> Int $i {
+    my Int $j=$i;
+    my Int $sum = 1;
+    my Str $solution="1";
+    my int $moves=0;
+    for ^$bits {
+        if $j +& 0x1 == 1 {
+            $sum+=1;
+            last if $sum>TARGET;
+            $solution~="+1";
+        } else {
+            $sum*=2;
+            last if $sum>TARGET;
+            $solution~="x2";
+        }
+        $j=$j +> 1;
+        $moves++;
+        if $sum==TARGET {
+            last;
+        }
+    }
+    if $sum==TARGET and $moves < $bestSolutionMoves {
+        $bestSolution=$solution ~ "=" ~ TARGET;
+        $bestSolutionMoves=$moves;
+    }
+}
+
+say "$bestSolution in $bestSolutionMoves moves";
+