Robbie Hatley's Solutions To The Weekly Challenge #231

For those not familiar with "The Weekly Challenge", it is a weekly programming puzzle, usually with two parts, cycling every Sunday. You can find it here:

The Weekly Challenge

This week (2023-08-20 through 2023-08-26) is weekly challenge #230.

Task 1 is as follows:

Task 1: Min Max
Submitted by: Mohammad S Anwar
You are given an array of distinct integers. Write a script to find all
elements which are neither minimum nor maximum. Return -1 if you can’t.

Example 1:
Input: @ints = (3, 2, 1, 4)
Output: (3, 2)
(The minimum is 1 and maximum is 4 in the given array. So (3, 2) are
the elements which are neither min nor max.)

Example 2:
Input: @ints = (3, 1)
Output: -1
(With only two distinct elements, each element is either min or max.)

Example 3:
Input: @ints = (2, 1, 3)
Output: (2)
(The minimum is 1 and maximum is 3 in the given array. So the only
element that's neither min nor max is 2.)

I suppose I could use CPAN, but I feel like rolling my own tonight. Since the elements were specified to be "distinct", I'll start by sorting the array:

my @sorted = sort {$a<=>$b} @array;

Then the first element will be min and the last element will be max:

my $min = shift @sorted;
my $max = pop @sorted;

Then just store the middle elements in an array:

my @middle;
map {push @middle, $_ if $_ != $min && $_ != $max} @ints;

The script I came up with is this:

Robbie Hatley's Solution to The Weekly Challenge 231-1

Task 2 is as follows:

Task 2: Senior Citizens
Submitted by: Mohammad S Anwar
You are given a list of passenger details in the form “9999999999A1122”,
where 9 denotes the phone number, A the sex, 1 the age, and 2 the seat number.
Write a script to return the count of all senior citizens (persons with
age >= 60).

Example 1:
Input: @list = ("7868190130M7522","5303914400F9211","9273338290F4010")
Ouput: 2
(The age of the passengers in the given list are 75, 92 and 40, so we
have only 2 senior citizens.)

Example 2:
Input: @list = ("1313579440F2036","2921522980M5644")
Ouput: 0
(All passengers have age < 60.)

My approach to solving this was, for each "detail", increment a counter each time an age 60+ is seen, being careful to strip any leading 0 from the age (else octal!!!):

my $senior_count = 0;
map {++$senior_count if (0 + ((substr $_, 11, 2) =~ s/^0//r)) >= 60} @$aref;

Here's the script I wrote:

Robbie Hatley's Solution to The Weekly Challenge 231-2

That's it for 231; see you on 232!