Merge pull request #12941 from packy/master

Challenge 345 solutions by Packy Anderson

10 files changed, 301 insertions, 1 deletions

diff --git a/challenge-345/packy-anderson/README.md b/challenge-345/packy-anderson/README.md
index dfffb8191c..b26414818b 100644
--- a/challenge-345/packy-anderson/README.md
+++ b/challenge-345/packy-anderson/README.md
@@ -23,4 +23,4 @@
 
 ## Blog Post
 
-[Perl Weekly Challenge: A-ray Sunshine!](https://packy.dardan.com/b/ct)
+[Perl Weekly Challenge: Teach Them How To Say PWC...](https://packy.dardan.com/b/dD)
diff --git a/challenge-345/packy-anderson/blog.txt b/challenge-345/packy-anderson/blog.txt
new file mode 100644
index 0000000000..2cfc877acc
--- /dev/null
+++ b/challenge-345/packy-anderson/blog.txt
@@ -0,0 +1 @@
+https://packy.dardan.com/b/dD
\ No newline at end of file
diff --git a/challenge-345/packy-anderson/elixir/ch-1.exs b/challenge-345/packy-anderson/elixir/ch-1.exs
new file mode 100755
index 0000000000..3668a2aec2
--- /dev/null
+++ b/challenge-345/packy-anderson/elixir/ch-1.exs
@@ -0,0 +1,42 @@
+#!/usr/bin/env elixir
+
+defmodule PWC do
+  def reduce_fn(i, {peaks, ints}) do
+    cond do
+      i != 0 && Enum.at(ints,i-1) > Enum.at(ints,i) ->
+        {i, {peaks, ints}}
+      i != length(ints) && Enum.at(ints,i+1) > Enum.at(ints,i) ->
+        {i, {peaks, ints}}
+      true ->
+        {i, {peaks ++ [i], ints}}
+    end
+  end
+
+  def peak_positions(ints) do
+    {_, {peaks, _}} = 0..length(ints)-1
+      |> Enum.to_list
+      |> Enum.map_reduce({[], ints}, &reduce_fn/2)
+    peaks
+  end
+
+  def solution(ints) do
+    IO.puts("Input: @ints = (" <> Enum.join(ints, ", ") <> ")")
+    peaks = peak_positions(ints)
+    IO.puts("Output: (" <> Enum.join(peaks, ", ") <> ")")
+  end
+end
+
+IO.puts("Example 1:")
+PWC.solution([1, 3, 2])
+
+IO.puts("\nExample 2:")
+PWC.solution([2, 4, 6, 5, 3])
+
+IO.puts("\nExample 3:")
+PWC.solution([1, 2, 3, 2, 4, 1])
+
+IO.puts("\nExample 4:")
+PWC.solution([5, 3, 1])
+
+IO.puts("\nExample 5:")
+PWC.solution([1, 5, 1, 5, 1, 5, 1])
diff --git a/challenge-345/packy-anderson/elixir/ch-2.exs b/challenge-345/packy-anderson/elixir/ch-2.exs
new file mode 100755
index 0000000000..6abe9fcfd3
--- /dev/null
+++ b/challenge-345/packy-anderson/elixir/ch-2.exs
@@ -0,0 +1,44 @@
+#!/usr/bin/env elixir
+
+defmodule PWC do
+  def last_visitor([], _, ans, _), do: ans
+
+  def last_visitor([i | ints], seen, ans, x) do
+    {seen, ans, x} = if i > 0 do
+      {[i] ++ seen, ans, x} # insert at front of @seen
+    else
+      if x < length(seen) do # if $x < len(@seen)
+        # append seen[x] to @ans
+        {seen, ans ++ [Enum.at(seen, x)], x+1}
+      else
+        {seen, ans ++ [-1], x+1} # append -1 to @ans
+      end
+    end
+    last_visitor(ints, seen, ans, x)
+  end
+
+  def last_visitor(ints) do
+    last_visitor(ints, [], [], 0)
+  end
+
+  def solution(ints) do
+    IO.puts("Input: @ints = (" <> Enum.join(ints, ", ") <> ")")
+    out = last_visitor(ints)
+    IO.puts("Output: (" <> Enum.join(out, ", ") <> ")")
+  end
+end
+
+IO.puts("Example 1:")
+PWC.solution([5, -1, -1])
+
+IO.puts("\nExample 2:")
+PWC.solution([3, 7, -1, -1, -1])
+
+IO.puts("\nExample 3:")
+PWC.solution([2, -1, 4, -1, -1])
+
+IO.puts("\nExample 4:")
+PWC.solution([10, 20, -1, 30, -1, -1])
+
+IO.puts("\nExample 5:")
+PWC.solution([-1, -1, 5, -1])
diff --git a/challenge-345/packy-anderson/perl/ch-1.pl b/challenge-345/packy-anderson/perl/ch-1.pl
new file mode 100755
index 0000000000..764a8d3501
--- /dev/null
+++ b/challenge-345/packy-anderson/perl/ch-1.pl
@@ -0,0 +1,32 @@
+#!/usr/bin/env perl
+use v5.40;
+
+sub peakPositions(@ints) {
+  my @peaks;
+  foreach my $i (0 .. $#ints) {
+    next unless $i == 0      || $ints[$i - 1] <= $ints[$i];
+    next unless $i == $#ints || $ints[$i + 1] <= $ints[$i];
+    push @peaks, $i;
+  }
+  return @peaks;
+}
+
+sub solution($ints) {
+  say 'Input: @ints = (' . join(', ', @$ints) . ')';
+  say 'Output: (' . join(', ', peakPositions(@$ints)) . ')';
+}
+
+say "Example 1:";
+solution([1, 3, 2]);
+
+say "\nExample 2:";
+solution([2, 4, 6, 5, 3]);
+
+say "\nExample 3:";
+solution([1, 2, 3, 2, 4, 1]);
+
+say "\nExample 4:";
+solution([5, 3, 1]);
+
+say "\nExample 5:";
+solution([1, 5, 1, 5, 1, 5, 1]);
diff --git a/challenge-345/packy-anderson/perl/ch-2.pl b/challenge-345/packy-anderson/perl/ch-2.pl
new file mode 100755
index 0000000000..3c787c8e4a
--- /dev/null
+++ b/challenge-345/packy-anderson/perl/ch-2.pl
@@ -0,0 +1,42 @@
+#!/usr/bin/env perl
+use v5.40;
+
+sub lastVisitor(@ints) {
+  my (@seen, @ans);
+  my $x = 0;
+  foreach my $i ( @ints ) {
+    if ($i > 0) {
+      unshift @seen, $i; # insert at front of @seen
+    }
+    else {
+      if ($x < @seen) {   # if $x < len(@seen)
+        push @ans, $seen[$x]; # append seen[x] to @ans
+      }
+      else {
+         push @ans, -1; # append -1 to @ans
+      }
+      $x++;
+    }
+  }
+  return @ans;
+}
+
+sub solution($ints) {
+  say 'Input: @ints = (' . join(', ', @$ints) . ')';
+  say 'Output: (' . join(', ', lastVisitor(@$ints)) . ')';
+}
+
+say "Example 1:";
+solution([5, -1, -1]);
+
+say "\nExample 2:";
+solution([3, 7, -1, -1, -1]);
+
+say "\nExample 3:";
+solution([2, -1, 4, -1, -1]);
+
+say "\nExample 4:";
+solution([10, 20, -1, 30, -1, -1]);
+
+say "\nExample 5:";
+solution([-1, -1, 5, -1]);
diff --git a/challenge-345/packy-anderson/python/ch-1.py b/challenge-345/packy-anderson/python/ch-1.py
new file mode 100755
index 0000000000..aadf0aba56
--- /dev/null
+++ b/challenge-345/packy-anderson/python/ch-1.py
@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+
+def peak_positions(ints):
+  peaks = []
+  for i in range(len(ints)):
+    if not (i == 0           or ints[i - 1] <= ints[i]):
+      continue
+    if not (i == len(ints)-1 or ints[i + 1] <= ints[i]):
+      continue
+    peaks.append(i)
+  return peaks
+
+def solution(ints):
+  print(f'Input: @ints = ({", ".join(map(str, ints))})')
+  print(f'Output: ({", ".join(map(str, peak_positions(ints)))})')
+
+print('Example 1:')
+solution([1, 3, 2])
+
+print('\nExample 2:')
+solution([2, 4, 6, 5, 3])
+
+print('\nExample 3:')
+solution([1, 2, 3, 2, 4, 1])
+
+print('\nExample 4:')
+solution([5, 3, 1])
+
+print('\nExample 5:')
+solution([1, 5, 1, 5, 1, 5, 1])
diff --git a/challenge-345/packy-anderson/python/ch-2.py b/challenge-345/packy-anderson/python/ch-2.py
new file mode 100755
index 0000000000..a9ac243d17
--- /dev/null
+++ b/challenge-345/packy-anderson/python/ch-2.py
@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+
+def last_visitor(ints):
+  seen = []
+  ans = []
+  x = 0
+  for i in ints:
+    if i > 0:
+      seen.insert(0, i) # insert at front of @seen
+    else:
+      if x < len(seen):   # if $x < len(@seen)
+        ans.append( seen[x] ) # append seen[x] to @ans
+      else:
+        ans.append( -1 ) # append -1 to @ans
+      x += 1
+  return ans
+
+def solution(ints):
+  print(f'Input: @ints = ({", ".join(map(str, ints))})')
+  print(f'Output: ({", ".join(map(str, last_visitor(ints)))})')
+
+print('Example 1:')
+solution([5, -1, -1])
+
+print('\nExample 2:')
+solution([3, 7, -1, -1, -1])
+
+print('\nExample 3:')
+solution([2, -1, 4, -1, -1])
+
+print('\nExample 4:')
+solution([10, 20, -1, 30, -1, -1])
+
+print('\nExample 5:')
+solution([-1, -1, 5, -1])
diff --git a/challenge-345/packy-anderson/raku/ch-1.raku b/challenge-345/packy-anderson/raku/ch-1.raku
new file mode 100755
index 0000000000..1acc238c87
--- /dev/null
+++ b/challenge-345/packy-anderson/raku/ch-1.raku
@@ -0,0 +1,32 @@
+#!/usr/bin/env raku
+use v6;
+
+sub peakPositions(@ints) {
+  my @peaks;
+  for 0..@ints.end -> $i {
+    next unless $i == 0         || @ints[$i - 1] <= @ints[$i];
+    next unless $i == @ints.end || @ints[$i + 1] <= @ints[$i];
+    @peaks.push($i);
+  }
+  return @peaks;
+}
+
+sub solution(@ints) {
+  say 'Input: @ints = (' ~ @ints.join(', ') ~ ')';
+  say 'Output: (' ~ peakPositions(@ints).join(', ') ~ ')';
+}
+
+say "Example 1:";
+solution([1, 3, 2]);
+
+say "\nExample 2:";
+solution([2, 4, 6, 5, 3]);
+
+say "\nExample 3:";
+solution([1, 2, 3, 2, 4, 1]);
+
+say "\nExample 4:";
+solution([5, 3, 1]);
+
+say "\nExample 5:";
+solution([1, 5, 1, 5, 1, 5, 1]);
diff --git a/challenge-345/packy-anderson/raku/ch-2.raku b/challenge-345/packy-anderson/raku/ch-2.raku
new file mode 100755
index 0000000000..b48918b18c
--- /dev/null
+++ b/challenge-345/packy-anderson/raku/ch-2.raku
@@ -0,0 +1,42 @@
+#!/usr/bin/env raku
+use v6;
+
+sub lastVisitor(@ints) {
+  my (@seen, @ans);
+  my $x = 0;
+  for @ints -> $i {
+    if ($i > 0) {
+      @seen.unshift($i); # insert at front of @seen
+    }
+    else {
+      if ($x < @seen.elems) {   # if $x < len(@seen)
+        @ans.push( @seen[$x] ); # append seen[x] to @ans
+      }
+      else {
+        @ans.push( -1 ); # append -1 to @ans
+      }
+      $x++;
+    }
+  }
+  return @ans;
+}
+
+sub solution(@ints) {
+  say 'Input: @ints = (' ~ @ints.join(', ') ~ ')';
+  say 'Output: (' ~ lastVisitor(@ints).join(', ') ~ ')';
+}
+
+say "Example 1:";
+solution([5, -1, -1]);
+
+say "\nExample 2:";
+solution([3, 7, -1, -1, -1]);
+
+say "\nExample 3:";
+solution([2, -1, 4, -1, -1]);
+
+say "\nExample 4:";
+solution([10, 20, -1, 30, -1, -1]);
+
+say "\nExample 5:";
+solution([-1, -1, 5, -1]);