From cb308efd84d76ed1cb58546a2f897e65bcf38d7f Mon Sep 17 00:00:00 2001
From: Matthew Neleigh <matthew.neleigh@gmail.com>
Date: Fri, 6 May 2022 12:09:38 -0400
Subject: 	new file:   challenge-163/mattneleigh/perl/ch-1.pl 	new
 file:   challenge-163/mattneleigh/perl/ch-2.pl

---
 challenge-163/mattneleigh/perl/ch-1.pl |  82 +++++++++++++++++++++++++++
 challenge-163/mattneleigh/perl/ch-2.pl | 100 +++++++++++++++++++++++++++++++++
 2 files changed, 182 insertions(+)
 create mode 100755 challenge-163/mattneleigh/perl/ch-1.pl
 create mode 100755 challenge-163/mattneleigh/perl/ch-2.pl

diff --git a/challenge-163/mattneleigh/perl/ch-1.pl b/challenge-163/mattneleigh/perl/ch-1.pl
new file mode 100755
index 0000000000..36ed0ea48f
--- /dev/null
+++ b/challenge-163/mattneleigh/perl/ch-1.pl
@@ -0,0 +1,82 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use English;
+
+################################################################################
+# Begin main execution
+################################################################################
+
+my @sets = (
+    [ 1, 2, 3 ],
+    [ 2, 3, 4 ]
+);
+my $set;
+
+print("\n");
+
+foreach $set (@sets){
+    my @pairs = unique_pairs_from_list(@{$set});
+    my $sum = 0;
+    my $shown_work;
+
+    # Do the math and document it; this will be
+    # shared later...
+    $shown_work = sprintf(
+        "Since %s  =>  %s  =>  %d",
+        join(" + ", map("(".$_->[0]." & ".$_->[1].")", @pairs)),
+        join(
+            " + ",
+            map(
+                # Where the actual math happens... and also
+                # some output generation
+                { my $a = ($_->[0] & $_->[1]); $sum += $a; $a; }
+                @pairs
+            )
+        ),
+        $sum
+    );
+
+    printf("Input: \@n = (%s)\n", join(", ", @{$set}));
+    printf("Output: %d\n\n", $sum);
+    print("$shown_work\n\n\n");
+}
+
+exit(0);
+################################################################################
+# End main execution; subroutines follow
+################################################################################
+
+
+
+################################################################################
+# Generate a sequence of unique pairs of items from a list
+# Takes one argument:
+# * The list of things to group into pairs, which can contain any set of scalar
+#   values (e.g. (1, 2, 3) )
+# Returns on success:
+# * A list of array refs, each of which refers to a pair of values from the
+#   original list (e.g. ( [ 1, 2 ], [ 1, 3 ], [ 2, 3 ] ) )
+# Returns on error
+# * undef if the list contains fewer than two elements (no pairs are possible)
+################################################################################
+sub unique_pairs_from_list{
+
+    return(undef)
+        unless(scalar(@ARG) > 1);
+
+    my @pairs = ();
+
+    for my $i (0 .. ($#ARG - 1)){
+        for my $j (($i + 1) .. $#ARG){
+            push(@pairs, [$ARG[$i], $ARG[$j]]);
+        }
+    }
+
+    return(@pairs);
+
+}
+
+
+
diff --git a/challenge-163/mattneleigh/perl/ch-2.pl b/challenge-163/mattneleigh/perl/ch-2.pl
new file mode 100755
index 0000000000..f59bd349dd
--- /dev/null
+++ b/challenge-163/mattneleigh/perl/ch-2.pl
@@ -0,0 +1,100 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use English;
+
+use POSIX;
+
+################################################################################
+# Begin main execution
+################################################################################
+
+my @lists = (
+    # Given cases
+    [ 1, 2, 3, 4, 5 ],
+    [ 1, 3, 5, 7, 9 ],
+
+    # Additional test cases
+    [ 2, 4, 50, 83, 6, 5, 9 ]
+);
+my $list;
+
+print("\n");
+foreach $list (@lists){
+    my $listref = [];
+    my $digits;
+    my $summation = compute_list_summation($listref, @{$list});
+
+    printf(
+        "\nInput: \@n = (%s)\nOutput: %d\n\n",
+        join(", ", @{$list}),
+        $summation
+    );
+
+    # See how many digits we'll need to handle...
+    $digits = ceil(log($summation) / log(10));
+
+    # Stick the input list at the head of the list of
+    # summation stages and output them in a pretty
+    # fashion
+    unshift(@{$listref}, $list);
+    foreach(@{$listref}){
+        printf(
+            "%".(4 + scalar(@{$list}) * ($digits + 1))."s\n",
+            join(" ", map(sprintf("%".$digits."d", $_), @{$_}))
+        );
+    }
+    print("\n");
+
+}
+
+print("\n");
+
+exit(0);
+################################################################################
+# End main execution; subroutines follow
+################################################################################
+
+
+
+################################################################################
+# Perform a particular type of list summation on a list of numbers
+# Takes two arguments:
+# * An array reference for storage of lists from intermediate summation stages,
+#   if desired; if this argument is 'undef', no intermediate lists will be
+#   stored
+# * The list of numbers to process
+# Returns:
+# * The final value that results from the summation process
+################################################################################
+sub compute_list_summation{
+    my $global_listref = shift();
+
+    my @stage_list;
+
+    # Loop over the last N-1 numbers in the list
+    # and add the running total to a new list
+    shift();
+    push(@stage_list, $ARG[0]);
+    for my $i (1 .. $#ARG){
+        push(@stage_list, $stage_list[$#stage_list] + $ARG[$i]);
+    }
+
+    # Store the list if requested to do so
+    push(@{$global_listref}, \@stage_list)
+        if(defined($global_listref));
+
+    # If there was just one sum generated, return
+    # it
+    return($stage_list[0])
+        if(scalar(@stage_list) == 1);
+
+    # Otherwise call ourselves on the sum list,
+    # return what the deeper call found
+    return(compute_list_summation($global_listref, @stage_list));
+
+}
+
+
+
-- 
cgit