Challenge 321 solutions by Packy Anderson

  * Raku that maybe looks like Raku, but mostly like Perl
  * Perl
  * Python that definitely looks like Perl
  * Elixir that looks kinda like Elixir

1 blog post

10 files changed, 280 insertions, 1 deletions

diff --git a/challenge-321/packy-anderson/README.md b/challenge-321/packy-anderson/README.md
index 9ffd00fb24..0d605b134b 100644
--- a/challenge-321/packy-anderson/README.md
+++ b/challenge-321/packy-anderson/README.md
@@ -23,4 +23,4 @@
 
 ## Blog Post
 
-[Perl Weekly Challenge: Happy Mother's Day](https://packy.dardan.com/b/UZ)
+[Perl Weekly Challenge: Comparatively Distinct, but Great^H^H^H^H^HAverage](https://packy.dardan.com/b/Up)
diff --git a/challenge-321/packy-anderson/blog.txt b/challenge-321/packy-anderson/blog.txt
new file mode 100644
index 0000000000..0478708029
--- /dev/null
+++ b/challenge-321/packy-anderson/blog.txt
@@ -0,0 +1 @@
+https://packy.dardan.com/b/Up
\ No newline at end of file
diff --git a/challenge-321/packy-anderson/elixir/ch-1.exs b/challenge-321/packy-anderson/elixir/ch-1.exs
new file mode 100755
index 0000000000..590fcb09e5
--- /dev/null
+++ b/challenge-321/packy-anderson/elixir/ch-1.exs
@@ -0,0 +1,51 @@
+#!/usr/bin/env elixir
+
+defmodule PWC do
+  def distinctAverages([], step, explain, averages),
+    do: {explain, averages}
+
+  def distinctAverages(nums, step, explain, averages) do
+    {min, nums} = List.pop_at(nums, 0)
+    {max, nums} = List.pop_at(nums, -1)
+    avg = (min + max) / 2
+    # since in Elixir, this will always produce a float,
+    # we need to do a little more work to make sure avg is an
+    # integer when it has no fractional component
+    avg = cond do
+      avg == trunc(avg) -> trunc(avg)
+      true              -> avg
+    end
+    explain = explain <> "Step #{step}: Min = #{min}, "
+    explain = explain <> "Max = #{max}, Avg = #{avg}\n"
+    averages = averages |> Map.put(avg, 1)
+    distinctAverages(nums, step+1, explain, averages)
+  end
+
+  def distinctAverages(nums) do
+    {explain, averages} =
+        distinctAverages(Enum.sort(nums), 1, "", %{})
+    count = averages |> Map.keys |> length
+    {
+      count,
+      explain <> "\nThe count of distinct average is #{count}."
+    }
+  end
+
+  def solution(nums) do
+    IO.puts("Input: @nums = (" <> Enum.join(nums, ", ") <> ")")
+    {count, explain} = distinctAverages(nums)
+    IO.puts("Output: #{count}\n\n#{explain}")
+  end
+end
+
+IO.puts("Example 1:")
+PWC.solution([1, 2, 4, 3, 5, 6])
+
+IO.puts("\nExample 2:")
+PWC.solution([0, 2, 4, 8, 3, 5])
+
+IO.puts("\nExample 3:")
+PWC.solution([7, 3, 1, 0, 5, 9])
+
+IO.puts("\nExample 4:")
+PWC.solution([1, 9, 2, 6, 3, 4])
diff --git a/challenge-321/packy-anderson/elixir/ch-2.exs b/challenge-321/packy-anderson/elixir/ch-2.exs
new file mode 100755
index 0000000000..7da3ddeb8e
--- /dev/null
+++ b/challenge-321/packy-anderson/elixir/ch-2.exs
@@ -0,0 +1,30 @@
+#!/usr/bin/env elixir
+
+defmodule PWC do
+  defp repeatReplace(str) do
+    s = Regex.replace(~r/.\#/, str, "")
+    cond do
+      s != str -> repeatReplace(s)
+      true     -> s
+    end
+  end
+
+  def backspaceCompare(str1, str2) do
+    repeatReplace(str1) == repeatReplace(str2)
+  end
+
+  def solution(str1, str2) do
+    IO.puts("Input: $str1 = \"#{str1}\"")
+    IO.puts("       $str2 = \"#{str2}\"")
+    IO.puts("Output: #{ backspaceCompare(str1, str2) }" )
+  end
+end
+
+IO.puts("Example 1:")
+PWC.solution("ab#c", "ad#c")
+
+IO.puts("\nExample 2:")
+PWC.solution("ab##", "a#b#")
+
+IO.puts("\nExample 3:")
+PWC.solution("a#b", "c")
diff --git a/challenge-321/packy-anderson/perl/ch-1.pl b/challenge-321/packy-anderson/perl/ch-1.pl
new file mode 100755
index 0000000000..3cfd61003f
--- /dev/null
+++ b/challenge-321/packy-anderson/perl/ch-1.pl
@@ -0,0 +1,37 @@
+#!/usr/bin/env perl
+use v5.40;
+
+sub distinctAverages(@nums) {
+  @nums = sort @nums;
+  my ($explain, $step) = (q{}, 0);
+  my %averages =();
+  while (@nums) {
+    my ($min, $max) = (shift(@nums), pop(@nums));
+    my $avg = ($min + $max) / 2;
+    $step++;
+    $explain .= "Step $step: Min = $min, "
+             .  "Max = $max, Avg = $avg\n";
+    $averages{$avg}++;
+  }
+  my $count = scalar(keys %averages);
+  $explain .= "\nThe count of distinct average is $count.";
+  return $count, $explain;
+}
+
+sub solution($nums) {
+  say 'Input: @nums = (' . join(', ', @$nums) . ')';
+  my ($count, $explain) = distinctAverages(@$nums);
+  say "Output: $count\n\n$explain";
+}
+
+say "Example 1:";
+solution([1, 2, 4, 3, 5, 6]);
+
+say "\nExample 2:";
+solution([0, 2, 4, 8, 3, 5]);
+
+say "\nExample 3:";
+solution([7, 3, 1, 0, 5, 9]);
+
+say "\nExample 4:";
+solution([1, 9, 2, 6, 3, 4]);
diff --git a/challenge-321/packy-anderson/perl/ch-2.pl b/challenge-321/packy-anderson/perl/ch-2.pl
new file mode 100755
index 0000000000..6c50898042
--- /dev/null
+++ b/challenge-321/packy-anderson/perl/ch-2.pl
@@ -0,0 +1,23 @@
+#!/usr/bin/env perl
+use v5.40;
+
+sub backspaceCompare($str1, $str2) {
+  while ($str1 =~ s/.\#//) {}
+  while ($str2 =~ s/.\#//) {}
+  return $str1 eq $str2 ? 'true' : 'false';
+}
+
+sub solution($str1, $str2) {
+  say qq{Input: \$str1 = "$str1"};
+  say qq{       \$str2 = "$str2"};
+  say 'Output: ' . backspaceCompare($str1, $str2);
+}
+
+say "Example 1:";
+solution("ab#c", "ad#c");
+
+say "\nExample 2:";
+solution("ab##", "a#b#");
+
+say "\nExample 3:";
+solution("a#b", "c");
diff --git a/challenge-321/packy-anderson/python/ch-1.py b/challenge-321/packy-anderson/python/ch-1.py
new file mode 100755
index 0000000000..a39a0b68ec
--- /dev/null
+++ b/challenge-321/packy-anderson/python/ch-1.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+
+from collections import Counter
+
+def distinctAverages(nums):
+  nums.sort() # list.sort() works in place
+  explain, step = "", 0
+  averages = Counter()
+  while nums:
+    min, max = nums.pop(0), nums.pop(-1)
+    avg = (min + max) / 2
+    # since in Python, this will always produce a real number,
+    # we need to do a little more work to make sure avg is an
+    # integer when it has no fractional component
+    if avg == int(avg):
+      avg = int(avg)
+    step += 1
+    explain += (
+      f"Step {step}: Min = {min}, Max = {max}, Avg = {avg}\n"
+    )
+    averages[avg] += 1
+  count = len(list(averages))
+  explain += (
+    f"\nThe count of distinct average is {count}."
+  )
+  return count, explain
+
+def int_join(joiner, arr):
+  return joiner.join(map(lambda i: str(i), arr))
+
+def solution(nums):
+  print(f'Input: @nums = ({int_join(", ", nums)})')
+  count, explain = distinctAverages(nums)
+  print(f'Output: {count}\n\n{explain}')
+
+print('Example 1:')
+solution([1, 2, 4, 3, 5, 6])
+
+print('\nExample 2:')
+solution([0, 2, 4, 8, 3, 5])
+
+print('\nExample 3:')
+solution([7, 3, 1, 0, 5, 9])
+
+print('\nExample 4:')
+solution([1, 9, 2, 6, 3, 4])
\ No newline at end of file
diff --git a/challenge-321/packy-anderson/python/ch-2.py b/challenge-321/packy-anderson/python/ch-2.py
new file mode 100755
index 0000000000..e1f1bc7c82
--- /dev/null
+++ b/challenge-321/packy-anderson/python/ch-2.py
@@ -0,0 +1,28 @@
+#!/usr/bin/env python
+
+import re
+
+def backspaceCompare(str1, str2):
+  s1 = re.sub(r'.\#', "", str1)
+  while s1 != str1:
+    str1 = s1
+    s1 = re.sub(r'.\#', "", str1)
+  s2 = re.sub(r'.\#', "", str2)
+  while s2 != str2:
+    str2 = s2
+    s2 = re.sub(r'.\#', "", str2)
+  return s1 == s2
+
+def solution(str1, str2):
+  print(f'Input: $str1 = "{str1}"')
+  print(f'       $str2 = "{str2}"')
+  print(f'Output: { backspaceCompare(str1, str2) }')
+
+print('Example 1:')
+solution("ab#c", "ad#c")
+
+print('\nExample 2:')
+solution("ab##", "a#b#")
+
+print('\nExample 3:')
+solution("a#b", "c")
diff --git a/challenge-321/packy-anderson/raku/ch-1.raku b/challenge-321/packy-anderson/raku/ch-1.raku
new file mode 100755
index 0000000000..5abc7a0d4a
--- /dev/null
+++ b/challenge-321/packy-anderson/raku/ch-1.raku
@@ -0,0 +1,37 @@
+#!/usr/bin/env raku
+use v6;
+
+sub distinctAverages(@nums) {
+  @nums = @nums.sort;
+  my ($explain, $step) = (q{}, 0);
+  my %averages = Bag.new;
+  while (@nums) {
+    my ($min, $max) = (@nums.shift, @nums.pop);
+    my $avg = ($min + $max) / 2;
+    $step++;
+    $explain ~= "Step $step: Min = $min, "
+             ~  "Max = $max, Avg = $avg\n";
+    %averages{$avg}++;
+  }
+  $explain ~= "\nThe count of distinct average is "
+           ~  %averages.elems ~ ".";
+  return %averages.elems, $explain;
+}
+
+sub solution(@nums) {
+  say 'Input: @nums = (' ~ @nums.join(', ') ~ ')';
+  my ($count, $explain) = distinctAverages(@nums);
+  say "Output: $count\n\n$explain";
+}
+
+say "Example 1:";
+solution([1, 2, 4, 3, 5, 6]);
+
+say "\nExample 2:";
+solution([0, 2, 4, 8, 3, 5]);
+
+say "\nExample 3:";
+solution([7, 3, 1, 0, 5, 9]);
+
+say "\nExample 4:";
+solution([1, 9, 2, 6, 3, 4]);
\ No newline at end of file
diff --git a/challenge-321/packy-anderson/raku/ch-2.raku b/challenge-321/packy-anderson/raku/ch-2.raku
new file mode 100755
index 0000000000..5aea8ca321
--- /dev/null
+++ b/challenge-321/packy-anderson/raku/ch-2.raku
@@ -0,0 +1,26 @@
+#!/usr/bin/env raku
+use v6;
+
+sub backspaceCompare($str1, $str2) {
+  # if we pass in these as 'is rw', it expects to be passed
+  # a writable container, which a string literal is not.
+  # it's just easier to copy it to a writable container.
+  my $s1 = $str1; while ($s1 ~~ s/.\#//) {}
+  my $s2 = $str2; while ($s2 ~~ s/.\#//) {}
+  return $s1 eq $s2;
+}
+
+sub solution($str1, $str2) {
+  say qq{Input: \$str1 = "$str1"};
+  say qq{       \$str2 = "$str2"};
+  say 'Output: ' ~ backspaceCompare($str1, $str2);
+}
+
+say "Example 1:";
+solution("ab#c", "ad#c");
+
+say "\nExample 2:";
+solution("ab##", "a#b#");
+
+say "\nExample 3:";
+solution("a#b", "c");