Merge pull request #12103 from packy/master

Challenge 323 solutions by Packy Anderson

10 files changed, 403 insertions, 1 deletions

diff --git a/challenge-323/packy-anderson/README.md b/challenge-323/packy-anderson/README.md
index 766d853167..528307c718 100644
--- a/challenge-323/packy-anderson/README.md
+++ b/challenge-323/packy-anderson/README.md
@@ -23,4 +23,4 @@
 
 ## Blog Post
 
-[Perl Weekly Challenge: The array is rank, but the string is formatted](https://packy.dardan.com/b/VE)
+[Perl Weekly Challenge: Should five percent appear too small...](https://packy.dardan.com/b/Ve)
diff --git a/challenge-323/packy-anderson/blog.txt b/challenge-323/packy-anderson/blog.txt
new file mode 100644
index 0000000000..812fe5334f
--- /dev/null
+++ b/challenge-323/packy-anderson/blog.txt
@@ -0,0 +1 @@
+https://packy.dardan.com/b/Ve
\ No newline at end of file
diff --git a/challenge-323/packy-anderson/elixir/ch-1.exs b/challenge-323/packy-anderson/elixir/ch-1.exs
new file mode 100755
index 0000000000..711e1d33c0
--- /dev/null
+++ b/challenge-323/packy-anderson/elixir/ch-1.exs
@@ -0,0 +1,43 @@
+#!/usr/bin/env elixir
+
+defmodule PWC do
+  defp fmt(num) do
+    String.pad_leading(to_string(num), 2)
+  end
+
+  def incDec([], x, explain), do:
+    {x, Enum.join(explain, "\n")}
+
+  def incDec([op | operations], x, explain) do
+    old_x = x
+    {x, o} = cond do
+      String.contains?(op, "++") ->
+        { x + 1, "+" }
+      true ->
+        { x - 1, "-" }
+    end
+    incDec(operations, x, explain ++ [
+      "Operation \"#{op}\" => #{fmt(old_x)} #{o} 1 => #{fmt(x)}"
+    ])
+  end
+
+  def incDec(operations) do
+    incDec(operations, 0, [])
+  end
+
+  def solution(operations) do
+    display = "\"" <> Enum.join(operations, "\", \"") <> "\""
+    IO.puts("Input: @operations = (#{display})")
+    {output, explain} = incDec(operations)
+    IO.puts("Output: #{output}\n\n#{explain}")
+  end
+end
+
+IO.puts("Example 1:")
+PWC.solution(["--x", "x++", "x++"])
+
+IO.puts("\nExample 2:")
+PWC.solution(["x++", "++x", "x++"])
+
+IO.puts("\nExample 3:")
+PWC.solution(["x++", "++x", "--x", "x--"])
diff --git a/challenge-323/packy-anderson/elixir/ch-2.exs b/challenge-323/packy-anderson/elixir/ch-2.exs
new file mode 100755
index 0000000000..5321ca5897
--- /dev/null
+++ b/challenge-323/packy-anderson/elixir/ch-2.exs
@@ -0,0 +1,89 @@
+#!/usr/bin/env elixir
+
+defmodule PWC do
+  defp fmt(num) do
+    cond do
+      num == 0 ->
+        0 # don't format a zero value
+      true ->
+        :erlang.float_to_binary(num, [decimals: 2])
+    end
+  end
+
+  defp plusJoin(arr), do:
+    Enum.join(arr, " + ")
+
+  def taxAmt([], _, _, operations, subtotals, total) do
+    # there's no more brackets, return the summary
+    {
+      total,
+      "Total Tax => #{plusJoin(operations)}\n" <>
+      "          => #{plusJoin(subtotals)}\n" <>
+      "          => #{fmt(total)}"
+    }
+  end
+
+  def taxAmt(_, income, _, operations, subtotals, total)
+    when income == 0 do
+    # there's no more income to tax, skip to the end
+    taxAmt([], 0, 0, operations, subtotals, total)
+  end
+
+  def taxAmt([tax | remaining], income, last_max, operations,
+             subtotals, total) do
+    # the maximum amount to tax at this rate is the first
+    # element of the tax bracket; but we need to adjust this
+    # amount to be relative to the amount of last bracket
+    max  = List.first(tax) - last_max
+    # the tax rate is the second element of the bracket
+    rate = List.last(tax)
+    # the amount to be taxed at this rate
+    amt = min(income, max)
+    # calculate the tax
+    tax = amt * rate/100
+
+    taxAmt(
+      remaining,
+      # we've just taxed amt, so remove it from income
+      income - amt,
+      # adjust the last rate for the next loop
+      max + last_max,
+      # save the steps so we can display them at the end
+      operations ++ ["(#{amt} * #{rate}/100)"],
+      # make sure we display to 100ths place
+      # if we hace a non-zero tax amount
+      subtotals  ++ ["#{fmt(tax)}"],
+      total + tax
+    )
+  end
+
+  def taxAmt(income, tax) do
+    if income == 0 do
+      { 0, "" } # special case
+    else
+      taxAmt(tax, income, 0, [], [], 0)
+    end
+  end
+
+  defp fmtArray(t, arr) do
+    arr = arr ++ [ "[#{List.first(t)},#{List.last(t)}]" ]
+    { t, arr }
+  end
+
+  def solution(income, tax) do
+    {_, brackets} = Enum.map_reduce(tax, [], &fmtArray/2)
+    display = Enum.join(brackets, ", ")
+    IO.puts("Input: $income = #{income}, @tax = (#{display})")
+    {total, explain} = taxAmt(income, tax)
+    IO.puts("Output: #{total}\n\n#{explain}")
+  end
+end
+
+IO.puts("Example 1:")
+PWC.solution(10, [[3, 50], [7, 10], [12,25]])
+
+IO.puts("\nExample 2:")
+PWC.solution(2, [[1, 0], [4, 25], [5,50]])
+
+IO.puts("\nExample 3:")
+PWC.solution(0, [[2, 50],])
diff --git a/challenge-323/packy-anderson/perl/ch-1.pl b/challenge-323/packy-anderson/perl/ch-1.pl
new file mode 100755
index 0000000000..3ec5d260c9
--- /dev/null
+++ b/challenge-323/packy-anderson/perl/ch-1.pl
@@ -0,0 +1,32 @@
+#!/usr/bin/env perl
+use v5.40;
+
+sub incDec(@operations) {
+  my ($x, $old_x, $o) = (0, 0, q{});
+  my @explain;
+  for my $op ( @operations ) {
+    $x = ($op =~ /\+\+/) ? $x + 1 : $x - 1;
+    $o = ($op =~ /\+\+/) ?   '+'  :   '-';
+    push @explain,
+      sprintf 'Operation "%s" => %2d %s 1 => %2d',
+                         $op, $old_x, $o, $x
+    ;
+    $old_x = $x;
+  }
+  return ($x, join("\n", @explain));
+}
+
+sub solution($operations) {
+  say 'Input: @operations = ("' . join('", "', @$operations) . '")';
+  my ($output, $explain) = incDec(@$operations);
+  say "Output: $output\n\n$explain";
+}
+
+say "Example 1:";
+solution(["--x", "x++", "x++"]);
+
+say "\nExample 2:";
+solution(["x++", "++x", "x++"]);
+
+say "\nExample 3:";
+solution(["x++", "++x", "--x", "x--"]);
diff --git a/challenge-323/packy-anderson/perl/ch-2.pl b/challenge-323/packy-anderson/perl/ch-2.pl
new file mode 100755
index 0000000000..1239856bf6
--- /dev/null
+++ b/challenge-323/packy-anderson/perl/ch-2.pl
@@ -0,0 +1,57 @@
+#!/usr/bin/env perl
+use v5.40;
+
+use List::AllUtils qw( min sum );
+
+sub taxAmt($income, @tax) {
+  return (0, "") if $income == 0; # special case
+
+  my $last_max = 0;
+  my @operations;
+  my @subtotals;
+  for my $bracket (@tax) {
+    my($max, $rate) = @$bracket;
+    # adjust the maximum amount at this rate
+    # to be relative to the last rate
+    $max -= $last_max;
+    # the amount to be taxed at this rate
+    my $amt = min($income, $max);
+    my $tax = $amt * $rate/100;
+    # make sure we display to 100ths place
+    # if we hace a non-zero tax amount
+    $tax = sprintf '%0.2f', $tax if $tax > 0;
+    # save the steps so we can display them at the end
+    push @operations, "($amt * $rate/100)";
+    push @subtotals, $tax;
+    # we've just taxed $amt, so remove it from $income
+    $income -= $amt; 
+    # adjust the last rate for the next loop
+    $last_max += $max;
+    # bail if there's no more income
+    last if $income <= 0;
+  }
+  my $total = sum @subtotals;
+  $total = sprintf '%0.2f', $total if $total > 0;
+  my $explain = "Total Tax => " . join(' + ', @operations) . "\n"
+              . "          => " . join(' + ', @subtotals) . "\n"
+              . "          => $total";
+
+  return $total, $explain;
+}
+
+sub solution($income, $tax) {
+  my @display = map { "[" . join(',', @$_) . "]" } @$tax;
+  say "Input: \$income = $income, "
+    . "\@tax = (" . join(', ', @display) . ")";
+  my ($output, $explain) = taxAmt($income, @$tax);
+  say "Output: $output\n\n$explain";
+}
+
+say "Example 1:";
+solution(10, [[3, 50], [7, 10], [12,25]]);
+
+say "\nExample 2:";
+solution(2, [[1, 0], [4, 25], [5,50]]);
+
+say "\nExample 3:";
+solution(0, [[2, 50],]);
diff --git a/challenge-323/packy-anderson/python/ch-1.py b/challenge-323/packy-anderson/python/ch-1.py
new file mode 100755
index 0000000000..5cbccba4aa
--- /dev/null
+++ b/challenge-323/packy-anderson/python/ch-1.py
@@ -0,0 +1,33 @@
+#!/usr/bin/env python
+
+def incDec(operations):
+  x = 0
+  old_x = 0
+  o = ''
+  explain = []
+  for op in operations:
+    x = x + 1 if "++" in op else x - 1
+    o =  '+'  if "++" in op else  '-'
+    explain.append(
+      'Operation "{}" => {:2d} {} 1 => {:2d}'.format(
+                  op,    old_x, o,       x
+      )
+    )
+    old_x = x
+  return x, "\n".join(explain)
+
+def solution(operations):
+  display = '"' + '", "'.join(operations) + '"'
+  print(f'Input: @operations = ({display})')
+  output, explain = incDec(operations)
+  print(f'Output: {output}\n\n{explain}')
+
+
+print('Example 1:')
+solution(["--x", "x++", "x++"])
+
+print('\nExample 2:')
+solution(["x++", "++x", "x++"])
+
+print('\nExample 3:')
+solution(["x++", "++x", "--x", "x--"])
diff --git a/challenge-323/packy-anderson/python/ch-2.py b/challenge-323/packy-anderson/python/ch-2.py
new file mode 100755
index 0000000000..c5c646192d
--- /dev/null
+++ b/challenge-323/packy-anderson/python/ch-2.py
@@ -0,0 +1,62 @@
+#!/usr/bin/env python
+
+def fmt(num):
+  if num > 0:
+    # display to 100ths place
+    return '{:0.2f}'.format(num)
+  else:
+    # format it as a string
+    return f"{int(num)}"
+
+def taxAmt(income, tax):
+  if income == 0:
+    return 0, "" # special case
+
+  last_max = 0
+  total = 0
+  operations = []
+  subtotals = []
+  for max_income, rate in tax:
+    # adjust the maximum amount at this rate
+    # to be relative to the last rate
+    max_income -= last_max
+    # the amount to be taxed at this rate
+    amt = min(income, max_income)
+    tax = amt * rate/100
+    total += tax
+    # make sure we display to 100ths place
+    # if we hace a non-zero tax amount
+    tax = fmt(tax)
+    # save the steps so we can display them at the end
+    operations.append(f"({amt} * {rate}/100)")
+    subtotals.append(tax)
+    # we've just taxed $amt, so remove it from $income
+    income -= amt
+    # adjust the last rate for the next loop
+    last_max += max_income
+    # bail if there's no more income
+    if income <= 0: break
+
+  return (
+    total,
+    "Total Tax => " + ' + '.join(operations) + "\n" +
+    "          => " + ' + '.join(subtotals) + "\n" +
+    "          => " + fmt(total)
+  )
+
+def solution(income, tax):
+  brackets = [ f"[{t[0]},{t[1]}]" for t in tax ]
+  display = ", ".join(brackets)
+  print(f'Input: $income = {income}, @tax = ({display})')
+  output, explain = taxAmt(income, tax)
+  print(f'Output: {output}\n\n{explain}')
+
+
+print('Example 1:')
+solution(10, [[3, 50], [7, 10], [12,25]])
+
+print('\nExample 2:')
+solution(2, [[1, 0], [4, 25], [5,50]])
+
+print('\nExample 3:')
+solution(0, [[2, 50],])
diff --git a/challenge-323/packy-anderson/raku/ch-1.raku b/challenge-323/packy-anderson/raku/ch-1.raku
new file mode 100755
index 0000000000..213e6498c7
--- /dev/null
+++ b/challenge-323/packy-anderson/raku/ch-1.raku
@@ -0,0 +1,31 @@
+#!/usr/bin/env raku
+use v6;
+
+sub incDec(@operations) {
+  my ($x, $old_x, $o) = (0, 0, q{});
+  my @explain;
+  for @operations -> $op {
+    ($x, $o) = ($op ~~ /\+\+/) ?? ($x + 1, '+') !! ($x - 1, '-');
+    @explain.push(
+      sprintf 'Operation "%s" => %2d %s 1 => %2d',
+                         $op, $old_x, $o, $x
+    );
+    $old_x = $x;
+  }
+  return ($x, @explain.join("\n"));
+}
+
+sub solution(@operations) {
+  say 'Input: @operations = ("' ~ @operations.join('", "') ~ '")';
+  my ($output, $explain) = incDec(@operations);
+  say "Output: $output\n\n$explain";
+}
+
+say "Example 1:";
+solution(["--x", "x++", "x++"]);
+
+say "\nExample 2:";
+solution(["x++", "++x", "x++"]);
+
+say "\nExample 3:";
+solution(["x++", "++x", "--x", "x--"]);
diff --git a/challenge-323/packy-anderson/raku/ch-2.raku b/challenge-323/packy-anderson/raku/ch-2.raku
new file mode 100755
index 0000000000..d5d2e3b63e
--- /dev/null
+++ b/challenge-323/packy-anderson/raku/ch-2.raku
@@ -0,0 +1,54 @@
+#!/usr/bin/env raku
+use v6;
+
+sub taxAmt($income is copy, @tax) {
+  return (0, "") if $income == 0; # special case
+
+  my $last_max = 0;
+  my @operations;
+  my @subtotals;
+  for @tax -> ($max is copy, $rate) {
+    # adjust the maximum amount at this rate
+    # to be relative to the last rate
+    $max -= $last_max;
+    # the amount to be taxed at this rate
+    my $amt = min($income, $max);
+    my $tax = $amt * $rate/100;
+    # make sure we display to 100ths place
+    # if we hace a non-zero tax amount
+    $tax = sprintf '%0.2f', $tax if $tax > 0;
+    # save the steps so we can display them at the end
+    @operations.push("($amt * $rate/100)");
+    @subtotals.push($tax);
+    # we've just taxed $amt, so remove it from $income
+    $income -= $amt; 
+    # adjust the last rate for the next loop
+    $last_max += $max;
+    # bail if there's no more income
+    last if $income <= 0;
+  }
+  my $total = @subtotals.sum;
+  $total = sprintf '%0.2f', $total if $total > 0;
+  my $explain = "Total Tax => " ~ @operations.join(' + ') ~ "\n"
+              ~ "          => " ~ @subtotals.join(' + ') ~ "\n"
+              ~ "          => $total";
+
+  return $total, $explain;
+}
+
+sub solution($income, @tax) {
+  my @display = @tax.map({ "[" ~ $_.join(',') ~ "]" });
+  say "Input: \$income = $income, "
+    ~ "\@tax = (" ~ @display.join(', ') ~ ")";
+  my ($output, $explain) = taxAmt($income, @tax);
+  say "Output: $output\n\n$explain";
+}
+
+say "Example 1:";
+solution(10, [[3, 50], [7, 10], [12,25]]);
+
+say "\nExample 2:";
+solution(2, [[1, 0], [4, 25], [5,50]]);
+
+say "\nExample 3:";
+solution(0, [[2, 50],]);