Merge pull request #11929 from packy/master

Challenge 318 solutions by Packy Anderson

10 files changed, 356 insertions, 1 deletions

diff --git a/challenge-318/packy-anderson/README.md b/challenge-318/packy-anderson/README.md
index dc50d472ee..c2f55fde69 100644
--- a/challenge-318/packy-anderson/README.md
+++ b/challenge-318/packy-anderson/README.md
@@ -1,2 +1,26 @@
-# Solutions by Packy Anderson.
+# Solutions by Packy Anderson
 
+## Raku
+
+* [Task 1](raku/ch-1.raku)
+* [Task 2](raku/ch-2.raku)
+
+## Perl
+
+* [Task 1](perl/ch-1.pl)
+* [Task 2](perl/ch-2.pl)
+
+## Guest Language: Python
+
+* [Task 1](python/ch-1.py)
+* [Task 2](python/ch-2.py)
+
+## Guest Language: Elixir
+
+* [Task 1](elixir/ch-1.exs)
+* [Task 2](elixir/ch-2.exs)
+
+
+## Blog Post
+
+[Perl Weekly Challenge: Group the Reverse Position](https://packy.dardan.com/b/Tp)
diff --git a/challenge-318/packy-anderson/blog.txt b/challenge-318/packy-anderson/blog.txt
new file mode 100644
index 0000000000..7a24911420
--- /dev/null
+++ b/challenge-318/packy-anderson/blog.txt
@@ -0,0 +1 @@
+https://packy.dardan.com/b/Tp
\ No newline at end of file
diff --git a/challenge-318/packy-anderson/elixir/ch-1.exs b/challenge-318/packy-anderson/elixir/ch-1.exs
new file mode 100755
index 0000000000..10891b3ec1
--- /dev/null
+++ b/challenge-318/packy-anderson/elixir/ch-1.exs
@@ -0,0 +1,32 @@
+#!/usr/bin/env elixir
+
+defmodule PWC do
+  def groupPosition(str) do
+    # will return a list of [entire_match, matching_char]
+    # tuples for each group matched
+    groups = Regex.scan(~r/([a-z])\1\1+/i, str)
+    if Enum.empty?(groups) do
+      "\"\""
+    else
+      groups
+        # grab the entire match from each group tuple
+        # and wrap it in quotes
+        |> Enum.map(&( "\"#{ List.first(&1) }\"" ))
+        |> Enum.join(", ")
+    end
+  end
+
+  def solution(str) do
+    IO.puts("Input: $str = \"#{str}\"")
+    IO.puts("Output: " <> groupPosition(str) )
+  end
+end
+
+IO.puts("Example 1:")
+PWC.solution("abccccd")
+
+IO.puts("\nExample 2:")
+PWC.solution("aaabcddddeefff")
+
+IO.puts("\nExample 3:")
+PWC.solution("abcdd")
diff --git a/challenge-318/packy-anderson/elixir/ch-2.exs b/challenge-318/packy-anderson/elixir/ch-2.exs
new file mode 100755
index 0000000000..57a553e874
--- /dev/null
+++ b/challenge-318/packy-anderson/elixir/ch-2.exs
@@ -0,0 +1,61 @@
+#!/usr/bin/env elixir
+
+defmodule PWC do
+  def reverseEquals(source, target, i, j) do
+    reversed = [] ++ if i > 0 do
+      Enum.slice(source, 0 .. i-1)
+    else
+      []
+    end
+    reversed = reversed ++ Enum.reverse(Enum.slice(source, i..j))
+    reversed = reversed ++ if j < length(source)-1 do
+      Enum.slice(source, j+1 .. length(source)-1)
+    else
+      []
+    end
+    cond do
+      reversed == target ->
+        { true, "#{i}-#{j}" }
+      # we've reached the end of the nested loops,
+      # so there's no solution
+      i == length(source)-2 and j == length(source)-1 ->
+        { false, "" }
+      # we're at the last j value, so let's increment i
+      # and set j = i+1
+      j == length(source)-1 ->
+        reverseEquals(source, target, i+1, i+2)
+      # just increment j
+      true ->
+        reverseEquals(source, target, i, j+1)
+    end
+  end
+
+  def reverseEquals(source, target)
+    when length(source) != length(target), do: { false, "" }
+
+  def reverseEquals(source, target)
+    when source == target, do: { true, "" }
+
+  def reverseEquals(source, target) do
+    reverseEquals(source, target, 0, 1)
+  end
+
+  def solution(source, target) do
+    IO.puts("Input: @source = (" <> Enum.join(source, ", ") <> ")")
+    IO.puts("       @target = (" <> Enum.join(target, ", ") <> ")")
+    {equals, elements} = reverseEquals(source, target)
+    IO.puts("Output: #{equals}")
+    if elements do
+      IO.puts("\nReverse elements: #{elements}")
+    end
+  end
+end
+
+IO.puts("Example 1:")
+PWC.solution([3, 2, 1, 4], [1, 2, 3, 4])
+
+IO.puts("\nExample 2:")
+PWC.solution([1, 3, 4], [4, 1, 3])
+
+IO.puts("\nExample 3:")
+PWC.solution([2], [2])
diff --git a/challenge-318/packy-anderson/perl/ch-1.pl b/challenge-318/packy-anderson/perl/ch-1.pl
new file mode 100755
index 0000000000..a1ccbee4d5
--- /dev/null
+++ b/challenge-318/packy-anderson/perl/ch-1.pl
@@ -0,0 +1,30 @@
+#!/usr/bin/env perl
+use v5.40;
+
+sub groupPosition($str) {
+  my @groups;
+  while ( $str =~ /([a-z])\1\1+/gip ) {
+    push @groups, ${^MATCH};
+  }
+  if (@groups) {
+    return join(", ", map { qq/"$_"/ } @groups);
+  }
+  else {
+    return qq/""/;
+  }
+}
+
+sub solution($str) {
+  say qq/Input: \$str = "$str"/;
+  my $result = groupPosition($str);
+  say qq/Output: $result/;
+}
+
+say "Example 1:";
+solution("abccccd");
+
+say "\nExample 2:";
+solution("aaabcddddeefff");
+
+say "\nExample 3:";
+solution("abcdd");
diff --git a/challenge-318/packy-anderson/perl/ch-2.pl b/challenge-318/packy-anderson/perl/ch-2.pl
new file mode 100755
index 0000000000..fed9c5fc3b
--- /dev/null
+++ b/challenge-318/packy-anderson/perl/ch-2.pl
@@ -0,0 +1,47 @@
+#!/usr/bin/env perl
+use v5.40;
+
+sub arrayEquals($a, $b) {
+  return join(',', @$a) eq join(',', @$b);
+}
+
+sub reverseEquals($source, $target) {
+  # deal with the trivial cases
+  if (@$source != @$target) {
+    # @source and @target are different lengths
+    return ("False", "");
+  }
+  if (arrayEquals($source, $target)) {
+    # they're already the same
+    return ("True", "");
+  }
+  # ok, now we start checking subarrays
+  foreach my $i ( 0 .. $#{$source} - 1 ) {
+    foreach my $j ( $i+1 .. $#{$source} ) {
+      my @reversed;
+      @reversed = @$source[0..$i-1] if $i > 0;
+      push @reversed, reverse @$source[$i..$j];
+      push @reversed, @$source[$j+1..$#{$source}]
+        if $j < $#{$source};
+      return ("True", "$i-$j") if arrayEquals(\@reversed, $target);
+    }
+  }
+  return ("False", "");
+}
+
+sub solution($source, $target) {
+  say 'Input: @source = (' . join(', ', @$source) . ')';
+  say '       @target = (' . join(', ', @$target) . ')';
+  my ($equals, $elements) = reverseEquals($source, $target);
+  say 'Output: ' . $equals;
+  say "\nReverse elements: " . $elements if $elements;
+}
+
+say "Example 1:";
+solution([3, 2, 1, 4], [1, 2, 3, 4]);
+
+say "\nExample 2:";
+solution([1, 3, 4], [4, 1, 3]);
+
+say "\nExample 3:";
+solution([2], [2]);
diff --git a/challenge-318/packy-anderson/python/ch-1.py b/challenge-318/packy-anderson/python/ch-1.py
new file mode 100755
index 0000000000..966e662963
--- /dev/null
+++ b/challenge-318/packy-anderson/python/ch-1.py
@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+
+import re
+
+def groupPosition(str):
+  # python doesn't support nested groups,
+  # so let's match just the first occurence
+  hasGroups = re.compile(r"([a-z])\1\1+", re.I)
+  groups = []
+
+  match = hasGroups.search(str)
+  while match:
+     # push the occurrence onto a list of groups
+     # the 0th group is the entire match
+     groups.append(match.group(0))
+     # then remove from the start of the string to
+     # the end of the first occurence
+     str = str[match.end():]
+     # and match against the new string
+     match = hasGroups.search(str)
+
+  if groups:
+    return ', '.join([ f'"{s}"' for s in groups ])
+  else:
+    return '""'
+
+def solution(str):
+    print(f'Input: $str = "{str}"')
+    print(f'Output: { groupPosition(str) }')
+
+print('Example 1:')
+solution("abccccd")
+
+print('\nExample 2:')
+solution("aaabcddddeefff")
+
+print('\nExample 3:')
+solution("abcdd")
diff --git a/challenge-318/packy-anderson/python/ch-2.py b/challenge-318/packy-anderson/python/ch-2.py
new file mode 100755
index 0000000000..2c129b2aec
--- /dev/null
+++ b/challenge-318/packy-anderson/python/ch-2.py
@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+
+def reverseEquals(source, target):
+  # deal with the trivial cases
+  if len(source) != len(target):
+    # @source and @target are different lengths
+    return (False, "")
+
+  if source == target:
+    # they're already the same
+    return (True, "")
+
+  # ok, now we start checking subarrays
+  for i in range(len(source)-1):
+    for j in range(i+1, len(source)):
+      rev = []
+      if i > 0:
+        rev = source[0:i]
+      rev.extend(list(reversed(source[i:j+1])))
+      if j < len(source)-1:
+        rev.extend(source[j+1:])
+      if rev == target:
+        return (True, f'{i}-{j}')
+
+  return (False, "")
+
+def comma_join(arr):
+    return ', '.join(map(lambda i: str(i), arr))
+
+def solution(source, target):
+    print(f'Input: @source = ({comma_join(source)})')
+    print(f'       @target = ({comma_join(target)})')
+    (equals, elements) = reverseEquals(source, target)
+    print(f'Output: {equals}')
+    if elements:
+        print(f'\nReverse elements: {elements}')
+
+print('Example 1:')
+solution([3, 2, 1, 4], [1, 2, 3, 4])
+
+print('\nExample 2:')
+solution([1, 3, 4], [4, 1, 3])
+
+print('\nExample 3:')
+solution([2], [2])
diff --git a/challenge-318/packy-anderson/raku/ch-1.raku b/challenge-318/packy-anderson/raku/ch-1.raku
new file mode 100755
index 0000000000..e524cd6c63
--- /dev/null
+++ b/challenge-318/packy-anderson/raku/ch-1.raku
@@ -0,0 +1,30 @@
+#!/usr/bin/env raku
+use v6;
+
+sub groupPosition($str) {
+  my @groups;
+  while ( $str ~~ m:i:c/ ((<[a..z]>)$0$0+) / ) {
+    @groups.push($0);
+  }
+  if (@groups) {
+    return @groups.map({ qq/"$_"/ }).join(", ");
+  }
+  else {
+    return qq/""/;
+  }
+}
+
+sub solution($str) {
+  say qq/Input: \$str = "$str"/;
+  my $result = groupPosition($str);
+  say qq/Output: $result/;
+}
+
+say "Example 1:";
+solution("abccccd");
+
+say "\nExample 2:";
+solution("aaabcddddeefff");
+
+say "\nExample 3:";
+solution("abcdd");
diff --git a/challenge-318/packy-anderson/raku/ch-2.raku b/challenge-318/packy-anderson/raku/ch-2.raku
new file mode 100755
index 0000000000..9948416dbd
--- /dev/null
+++ b/challenge-318/packy-anderson/raku/ch-2.raku
@@ -0,0 +1,47 @@
+#!/usr/bin/env raku
+use v6;
+
+sub arrayEquals(@a, @b) {
+  return @a.join(',') eq @b.join(',');
+}
+
+sub reverseEquals(@source, @target) {
+  # deal with the trivial cases
+  if (@source.elems != @target.elems) {
+    # @source and @target are different lengths
+    return (False, "");
+  }
+  if (arrayEquals(@source, @target)) {
+    # they're already the same
+    return (True, "");
+  }
+  # ok, now we start checking subarrays
+  for 0..@source.end - 1 -> $i {
+    for $i+1..@source.end -> $j {
+      my @reversed;
+      @reversed = @source[0..$i-1] if $i > 0;
+      @reversed.append(@source[$i..$j].reverse);
+      @reversed.append(@source[$j+1..@source.end])
+        if $j < @source.end;
+      return (True, "$i-$j") if arrayEquals(@reversed, @target);
+    }
+  }
+  return (False, "");
+}
+
+sub solution(@source, @target) {
+  say 'Input: @source = (' ~ @source.join(', ') ~ ')';
+  say '       @target = (' ~ @target.join(', ') ~ ')';
+  my ($equals, $elements) = reverseEquals(@source, @target);
+  say 'Output: ' ~ $equals;
+  say "\nReverse elements: " ~ $elements if $elements;
+}
+
+say "Example 1:";
+solution([3, 2, 1, 4], [1, 2, 3, 4]);
+
+say "\nExample 2:";
+solution([1, 3, 4], [4, 1, 3]);
+
+say "\nExample 3:";
+solution([2], [2]);