Smaller greater element

You are given an array of integers. Write a script to find the number of elements that have both a strictly smaller and greater element in the given array.

Examples

Example 1
Input: @int = (2,4)
Output: 0
Not enough elements in the array.

Example 2
Input: @int = (1, 1, 1, 1)
Output: 0

Example 3
Input: @int = (1, 1, 4, 8, 12, 12)
Output: 2
The elements are 4 and 8.

Example 4
Input: @int = (3, 6, 6, 9)
Output: 2
Both instances of 6.

Example 5
Input: @int = (0, -5, 10, -2, 4)
Output: 3
The elements are 0, -2, and 4.

Analysis

To sort or not to sort, as Hamlet didn't say.

Sorting is overkill, but it's 33C here and I'm looking for the easy answer, which is:

• Sort the array
• Count the elements that are more than $array[0] and less than $array[-1].

On a cooler day I might do a first pass through to find the largest and smallest, and a second pass to count the elements as above, but it would need to be a huge array to make an appreciable difference.

Peter maintains his well-established tradition of rendering intelligent explanations of the problems of the week tasks, 'Same Row Column' and 'Smaller Greater Element'. His take on these tasks is characterised by the ease of reading and clarity of the presented equations.

This review may cover either or both challenges for this week.

Try it 

Your input:

$array =

eg: 1, 2, 3, 4, 5, 6

⤡

#!/usr/bin/perl

# Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge/381/2

use v5.26;    # The Weekly Challenge - 2026-07-06
use utf8;     # Week 381 - task 2 - Smaller greater element
use warnings; # Peter Campbell Smith
binmode STDOUT, ':utf8';
use Encode;

smaller_greater_element(1, 1, 1, 1);
smaller_greater_element(4, 8, 12, 12, 1, 1);
smaller_greater_element(9, 6, 6, 3);
smaller_greater_element(0, -5, 10, -2, 4);

my @x;
push @x, int(rand(10)) + 1 for 1 .. 50;
smaller_greater_element(@x);

sub smaller_greater_element {
    
    my (@array, @explain, $n);
    
    # initialise
    say qq[\nInput:  ] . join(', ', @_);
    @array = sort {$a <=> $b} @_;
    
    # look for candidates
    for $n (0 .. $#array) {
        push @explain, $array[$n] if ($array[$n] > $array[0] and 
            $array[$n] < $array[-1]);
    }
    
    # report
    say qq[Output: ]  . (@explain ? (scalar @explain . 
        qq[ (] . join(', ', @explain) . ')') : 'none');
}

9 lines of code

Output from script

Input:  1, 1, 1, 1
Output: none

Input:  4, 8, 12, 12, 1, 1
Output: 2 (4, 8)

Input:  9, 6, 6, 3
Output: 2 (6, 6)

Input:  0, -5, 10, -2, 4
Output: 3 (-2, 0, 4)

Input:  5, 9, 5, 8, 4, 7, 6, 5, 5, 1, 5, 6, 3, 5, 10, 3, 3, 5, 3, 8,
   8, 3, 4, 7, 1, 10, 9, 2, 6, 5, 9, 4, 8, 3, 7, 9, 3, 5, 1, 8, 3, 5,
   8, 7, 8, 3, 3, 3, 4, 3
Output: 45 (2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5,
   5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8,
   9, 9, 9, 9)