DAJ 320 Blog

Author: jacoby

_posts/2025-05-08-lots-and-lots-of-integers-weekly-challenge-320.markdown

@@ -0,0 +1,125 @@
+---
+layout: post
+title: "Lots and Lots of Integers!: Weekly Challenge #320"
+author: "Dave Jacoby"
+date: "2025-05-08 18:06:51 -0400"
+categories: ""
+---
+
+Welcome to [**_Weekly Challenge #320!_**](https://theweeklychallenge.org/blog/perl-weekly-challenge-320/) This week's title is inspired by a video my child used to watch, [Lots and Lots of Jets and Planes!](https://www.youtube.com/watch?v=3fMGTHyYPTQ)
+
+### Task 1: Maximum Count
+
+> Submitted by: Mohammad Sajid Anwar
+> You are given an array of integers.
+>
+> Write a script to return the maximum between the number of positive and negative integers. Zero is neither positive nor negative.
+
+#### Let's Talk About It
+
+We get the count of positive and negative integers in a functional way. `grep` allows us to strip out the integers we want, and `scalar` gives us a count, rather than the values. Then I use a ternary operator to determinte whether the count of positive integers are highter than the count of negative integers, and `return` the higher count.
+
+#### Show Me The Code!
+
+```perl
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say state postderef signatures };
+
+my @examples = (
+
+    [ -3, -2, -1, 1, 2, 3 ],
+    [ -2, -1, 0,  0, 1 ],
+    [ 1,  2,  3,  4 ],
+);
+
+for my $example (@examples) {
+    my $str    = join ', ', $example->@*;
+    my $output = max_count( $example->@* );
+    say <<"END";
+    Input:  \$str = ($str)
+    Output: $output
+END
+}
+
+sub max_count(@ints) {
+    my $pos = scalar grep { $_ > 0 } @ints;
+    my $neg = scalar grep { $_ < 0 } @ints;
+    return $pos > $neg ? $pos : $neg;
+}
+```
+
+```text
+$ ./ch-1.pl
+    Input:  $str = (-3, -2, -1, 1, 2, 3)
+    Output: 3
+
+    Input:  $str = (-2, -1, 0, 0, 1)
+    Output: 2
+
+    Input:  $str = (1, 2, 3, 4)
+    Output: 4
+```
+
+# Task 2: Sum Difference
+
+> Submitted by: Mohammad Sajid Anwar  
+> You are given an array of positive integers.
+>
+> Write a script to return the absolute difference between digit sum and element sum of the given array.
+
+#### Let's Talk About It
+
+Because [List::Util](https://metacpan.org/pod/List::Util) gives us `sum0`, I use that. (Again, I agree with `sum0`'s behavior, not that it matters for most uses.) I use `map` and `split` to separate integers into separate digits, and then subtraction and `abs` to finish the math.
+
+#### Show Me The Code!
+
+```perl
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say state postderef signatures };
+
+use List::Util qw{ sum0 };
+
+my @examples = (
+
+    [ 1, 23, 4, 5 ],
+    [ 1, 2,  3, 4, 5 ],
+    [ 1, 2,  34 ],
+);
+
+for my $example (@examples) {
+    my $str    = join ', ', $example->@*;
+    my $output = sum_diff( $example->@* );
+    say <<"END";
+    Input:  \$str = ($str)
+    Output: $output
+END
+}
+
+sub sum_diff (@ints) {
+    my $digit_sum   = sum0 @ints;
+    my $element_sum = sum0 map { split //, $_ } @ints;
+    return abs $digit_sum - $element_sum;
+}
+```
+
+```text
+$ ./ch-2.pl
+    Input:  $str = (1, 23, 4, 5)
+    Output: 18
+
+    Input:  $str = (1, 2, 3, 4, 5)
+    Output: 0
+
+    Input:  $str = (1, 2, 34)
+    Output: 27
+
+ jacoby  Bishop  ~  win  320  $ 
+```
+
+#### If you have any questions or comments, I would be glad to hear it. Ask me on [Mastodon](https://mastodon.xyz/@jacobydave) or [make an issue on my blog repo.](https://github.com/jacoby/jacoby.github.io)