From a8e8a75796d9be05a2fc4ce38db216141b8aea5b Mon Sep 17 00:00:00 2001
From: Packy Anderson <packy@cpan.org>
Date: Mon, 25 Dec 2023 18:58:47 -0500
Subject: Challenge 249 solutions by Packy Anderson

  * Raku
  * Perl
  * Python

1 Blog post
---
 challenge-249/packy-anderson/README.md      | 82 ++++++++++++-----------------
 challenge-249/packy-anderson/blog.txt       |  1 +
 challenge-249/packy-anderson/perl/ch-1.pl   | 47 +++++++++++++++++
 challenge-249/packy-anderson/perl/ch-2.pl   | 39 ++++++++++++++
 challenge-249/packy-anderson/python/ch-1.py | 47 +++++++++++++++++
 challenge-249/packy-anderson/python/ch-2.py | 36 +++++++++++++
 challenge-249/packy-anderson/raku/ch-1.raku | 46 ++++++++++++++++
 challenge-249/packy-anderson/raku/ch-2.raku | 39 ++++++++++++++
 8 files changed, 288 insertions(+), 49 deletions(-)
 create mode 100644 challenge-249/packy-anderson/blog.txt
 create mode 100755 challenge-249/packy-anderson/perl/ch-1.pl
 create mode 100755 challenge-249/packy-anderson/perl/ch-2.pl
 create mode 100755 challenge-249/packy-anderson/python/ch-1.py
 create mode 100755 challenge-249/packy-anderson/python/ch-2.py
 create mode 100755 challenge-249/packy-anderson/raku/ch-1.raku
 create mode 100755 challenge-249/packy-anderson/raku/ch-2.raku

diff --git a/challenge-249/packy-anderson/README.md b/challenge-249/packy-anderson/README.md
index f08eb862a3..6682f66637 100644
--- a/challenge-249/packy-anderson/README.md
+++ b/challenge-249/packy-anderson/README.md
@@ -8,12 +8,16 @@ Sample output
 ```
 $ raku/ch-1.raku
 Example 1:
-Input: $str = "loveleetcode", $char = "e"
-Output: (3,2,1,0,1,0,0,1,2,2,1,0)
+Input: @ints = (3, 2, 3, 2, 2, 2)
+Output: (3, 3), (2, 2), (2, 2)
 
 Example 2:
-Input: $str = "aaab", $char = "b"
-Output: (3,2,1,0)
+Input: @ints = (1, 2, 3, 4)
+Output: ()
+
+Example 3:
+Input: @ints = (1, 2, 3, 4, 4, 3, 2, 1)
+Output: (1, 1), (4, 4), (3, 3), (2, 2)
 ```
 
 * [Task 2](raku/ch-2.raku)
@@ -22,28 +26,16 @@ Sample output
 ```
 $ raku/ch-2.raku
 Example 1:
-Input:  $a = [
-               [1, 2, 3, 4],
-               [5, 6, 7, 8],
-               [9, 10, 11, 12]
-             ]
-Output: $b = [
-               [14, 18, 22],
-               [30, 34, 38]
-             ]
+Input: $str = 'IDID'
+Output: (0, 4, 1, 3, 2)
 
 Example 2:
-Input:  $a = [
-               [1, 0, 0, 0],
-               [0, 1, 0, 0],
-               [0, 0, 1, 0],
-               [0, 0, 0, 1]
-             ]
-Output: $b = [
-               [2, 1, 0],
-               [1, 2, 1],
-               [0, 1, 2]
-             ]
+Input: $str = 'III'
+Output: (0, 1, 2, 3)
+
+Example 3:
+Input: $str = 'DDI'
+Output: (3, 2, 0, 1)
 ```
 
 ## Perl
@@ -54,12 +46,16 @@ Sample output
 ```
 $ perl/ch-1.pl
 Example 1:
-Input: $str = "loveleetcode", $char = "e"
-Output: (3,2,1,0,1,0,0,1,2,2,1,0)
+Input: @ints = (3, 2, 3, 2, 2, 2)
+Output: (2, 2), (2, 2), (3, 3)
 
 Example 2:
-Input: $str = "aaab", $char = "b"
-Output: (3,2,1,0)
+Input: @ints = (1, 2, 3, 4)
+Output: ()
+
+Example 3:
+Input: @ints = (1, 2, 3, 4, 4, 3, 2, 1)
+Output: (4, 4), (3, 3), (2, 2), (1, 1)
 ```
 
 * [Task 2](perl/ch-2.pl)
@@ -68,28 +64,16 @@ Sample output
 ```
 $ perl/ch-2.pl
 Example 1:
-Input:  $a = [
-               [1, 2, 3, 4],
-               [5, 6, 7, 8],
-               [9, 10, 11, 12]
-             ]
-Output: $b = [
-               [14, 18, 22],
-               [30, 34, 38]
-             ]
+Input: $str = 'IDID'
+Output: (0, 4, 1, 3, 2)
 
 Example 2:
-Input:  $a = [
-               [1, 0, 0, 0],
-               [0, 1, 0, 0],
-               [0, 0, 1, 0],
-               [0, 0, 0, 1]
-             ]
-Output: $b = [
-               [2, 1, 0],
-               [1, 2, 1],
-               [0, 1, 2]
-             ]
+Input: $str = 'III'
+Output: (0, 1, 2, 3)
+
+Example 3:
+Input: $str = 'DDI'
+Output: (3, 2, 0, 1)
 ```
 
 ## Guest Language: Python
@@ -98,4 +82,4 @@ Output: $b = [
 
 ## Blog Post
 
-[Perl Weekly Challenge: The Shortest Distance between Submatrix Sums](https://packy.dardan.com/b/Ff)
+[Perl Weekly Challenge: Stringy DI and Paired Equals](https://packy.dardan.com/b/Fv)
diff --git a/challenge-249/packy-anderson/blog.txt b/challenge-249/packy-anderson/blog.txt
new file mode 100644
index 0000000000..1adcf62852
--- /dev/null
+++ b/challenge-249/packy-anderson/blog.txt
@@ -0,0 +1 @@
+https://packy.dardan.com/b/Fv
\ No newline at end of file
diff --git a/challenge-249/packy-anderson/perl/ch-1.pl b/challenge-249/packy-anderson/perl/ch-1.pl
new file mode 100755
index 0000000000..ec399a13e6
--- /dev/null
+++ b/challenge-249/packy-anderson/perl/ch-1.pl
@@ -0,0 +1,47 @@
+#!/usr/bin/env perl
+use v5.38;
+
+sub equalPairs(@ints) {
+  my @pairs;
+  my %num_count;
+  # count how many of each int we have
+  foreach my $num ( @ints ) {
+    $num_count{$num}++;
+  }
+  # first, make sure we have even numbers of each integer
+  foreach my $k ( keys %num_count ) {
+    my $v = $num_count{$k};
+    next if $v % 2 == 0; # it's even, we can make pairs
+    return @pairs; # we have an odd number, can't make pairs
+  }
+  # now make pairs from those integers
+  foreach my $k ( keys %num_count ) {
+    my $count = $num_count{$k};
+    while ($count > 0) {
+      push @pairs, [$k, $k];
+      $count -= 2;
+    }
+  }
+  return @pairs;
+}
+
+sub solution(@ints) {
+  say 'Input: @ints = (' . join(', ', @ints) . ')';
+  my @pairs = equalPairs(@ints);
+  if (@pairs == 0) {
+    say 'Output: ()';
+  }
+  else {
+    @pairs = map { qq{($_->[0], $_->[1])} } @pairs;
+    say 'Output: ' . join(', ', @pairs);
+  }
+}
+
+say "Example 1:";
+solution(3, 2, 3, 2, 2, 2);
+
+say "\nExample 2:";
+solution(1, 2, 3, 4);
+
+say "\nExample 3:";
+solution(1, 2, 3, 4, 4, 3, 2, 1);
\ No newline at end of file
diff --git a/challenge-249/packy-anderson/perl/ch-2.pl b/challenge-249/packy-anderson/perl/ch-2.pl
new file mode 100755
index 0000000000..e24b164ac9
--- /dev/null
+++ b/challenge-249/packy-anderson/perl/ch-2.pl
@@ -0,0 +1,39 @@
+#!/usr/bin/env perl
+use v5.38;
+
+sub diStringMatch($str) {
+  my @permutation;
+  # first, generate the list of integers
+  # we're making permutations of
+  my @nums = 0 .. length($str);
+  # now let's generate our permutation
+  foreach my $c ( split(//, $str) ) {
+    if ($c eq 'D') {
+      # take the largest number available
+      push @permutation, pop(@nums);
+    }
+    else {
+      # take the smallest number available
+      push @permutation, shift(@nums);
+    }
+  }
+  # add last remaining number
+  push @permutation, $nums[0];
+
+  return @permutation;
+}
+
+sub solution($str) {
+  say qq{Input: \$str = '$str'};
+  my @permutation = diStringMatch($str);
+  say 'Output: (' . join(', ', @permutation) . ')';
+}
+
+say "Example 1:";
+solution("IDID");
+
+say "\nExample 2:";
+solution("III");
+
+say "\nExample 3:";
+solution("DDI");
\ No newline at end of file
diff --git a/challenge-249/packy-anderson/python/ch-1.py b/challenge-249/packy-anderson/python/ch-1.py
new file mode 100755
index 0000000000..228bb47da3
--- /dev/null
+++ b/challenge-249/packy-anderson/python/ch-1.py
@@ -0,0 +1,47 @@
+#!/usr/bin/env python
+
+from collections import Counter
+
+def equalPairs(nums):
+    pairs = []
+    num_count = Counter()
+    # count how many of each int we have
+    for num in nums:
+        num_count[num] += 1
+
+    # first, make sure we have even numbers of each integer
+    for k, v in dict(num_count).items():
+        if v % 2 == 0: # it's even, we can make pairs
+            continue
+        else:
+            return pairs # we have an odd number, no pairs
+
+    # now make pairs from those integers
+    for k, v in dict(num_count).items():
+        count = v # the values k, v are read-only
+        while count > 0:
+            pairs.append( [k, k] )
+            count -= 2
+
+    return pairs
+
+def comma_join(arr):
+    return ', '.join(map(lambda i: str(i), arr))
+
+def solution(nums):
+    print(f'Input: @ints = ({comma_join(nums)})')
+    pairs = equalPairs(nums)
+    if len(pairs) == 0:
+        print('Output: ()')
+    else:
+        pairs = [ f'({x[0]}, {x[1]})' for x in pairs ]
+        print(f"Output: { ', '.join(pairs) }")
+
+print('Example 1:')
+solution([3, 2, 3, 2, 2, 2])
+
+print('\nExample 2:')
+solution([1, 2, 3, 4])
+
+print('\nExample 3:')
+solution([1, 2, 3, 4, 4, 3, 2, 1])
\ No newline at end of file
diff --git a/challenge-249/packy-anderson/python/ch-2.py b/challenge-249/packy-anderson/python/ch-2.py
new file mode 100755
index 0000000000..8c3750f195
--- /dev/null
+++ b/challenge-249/packy-anderson/python/ch-2.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+
+def diStringMatch(str):
+    permutation = []
+    # first, generate the list of integers
+    # we're making permutations of
+    nums = list(range(len(str)+1))
+    # now let's generate our permutation
+    for c in str:
+        if c == 'D':
+            # take the largest number available
+            permutation.append( nums.pop(-1) )
+        else:
+            # take the smallest number available
+            permutation.append( nums.pop(0) )
+    # add last remaining number
+    permutation.append( nums[0] )
+
+    return permutation
+
+def comma_join(arr):
+    return ', '.join(map(lambda i: str(i), arr))
+
+def solution(str):
+    print(f'Input: $str = ({comma_join(str)})')
+    permutations = diStringMatch(str)
+    print(f'Output: ({comma_join(permutations)})')
+
+print('Example 1:')
+solution("IDID")
+
+print('\nExample 2:')
+solution("III")
+
+print('\nExample 3:')
+solution("DDI")
\ No newline at end of file
diff --git a/challenge-249/packy-anderson/raku/ch-1.raku b/challenge-249/packy-anderson/raku/ch-1.raku
new file mode 100755
index 0000000000..6daec9c767
--- /dev/null
+++ b/challenge-249/packy-anderson/raku/ch-1.raku
@@ -0,0 +1,46 @@
+#!/usr/bin/env raku
+use v6;
+
+sub equalPairs(@ints) {
+  my @pairs;
+  my %num_count;
+  # count how many of each int we have
+  for @ints -> $num {
+    %num_count{$num}++;
+  }
+  # first, make sure we have even numbers of each integer
+  for %num_count.kv -> $k, $v {
+    next if $v % 2 == 0; # it's even, we can make pairs
+    return @pairs; # we have an odd number, can't make pairs
+  }
+  # now make pairs from those integers
+  for %num_count.kv -> $k, $v {
+    my $count = $v; # the values $k, $v are read-only
+    while ($count > 0) {
+      @pairs.push( [$k, $k] );
+      $count -= 2;
+    }
+  }
+  return @pairs;
+}
+
+sub solution(@ints) {
+  say 'Input: @ints = (' ~ @ints.join(', ') ~ ')';
+  my @pairs = equalPairs(@ints);
+  if (@pairs == 0) {
+    say 'Output: ()';
+  }
+  else {
+    @pairs = @pairs.map({ qq{($_[0], $_[1])} });
+    say 'Output: ' ~ @pairs.join(', ');
+  }
+}
+
+say "Example 1:";
+solution([3, 2, 3, 2, 2, 2]);
+
+say "\nExample 2:";
+solution([1, 2, 3, 4]);
+
+say "\nExample 3:";
+solution([1, 2, 3, 4, 4, 3, 2, 1]);
diff --git a/challenge-249/packy-anderson/raku/ch-2.raku b/challenge-249/packy-anderson/raku/ch-2.raku
new file mode 100755
index 0000000000..44b853efd2
--- /dev/null
+++ b/challenge-249/packy-anderson/raku/ch-2.raku
@@ -0,0 +1,39 @@
+#!/usr/bin/env raku
+use v6;
+
+sub diStringMatch($str) {
+  my @permutation;
+  # first, generate the list of integers
+  # we're making permutations of
+  my @nums = 0 .. $str.chars;
+  # now let's generate our permutation
+  for $str.split('', :skip-empty) -> $c {
+    if ($c eq 'D') {
+      # take the largest number available
+      @permutation.push( @nums.pop() );
+    }
+    else {
+      # take the smallest number available
+      @permutation.push( @nums.shift() );
+    }
+  }
+  # add last remaining number
+  @permutation.push( @nums[0] );
+
+  return @permutation;
+}
+
+sub solution($str) {
+  say qq{Input: \$str = '$str'};
+  my @permutation = diStringMatch($str);
+  say 'Output: (' ~ @permutation.join(', ') ~ ')';
+}
+
+say "Example 1:";
+solution("IDID");
+
+say "\nExample 2:";
+solution("III");
+
+say "\nExample 3:";
+solution("DDI");
\ No newline at end of file
-- 
cgit