#!/bin/env perl

use strict;

use Data::Dumper;

use constant REQUIRED_FIELDS => qw/zero one two three four five six seven/;

my $a = [qw/three one two/];
print Data::Dumper->Dump([$a], ['a']);
verify($a);
exit;

sub verify {
    my $a = shift;

    my $fields = [REQUIRED_FIELDS];

    my $href = {};
    foreach my $e (@$a) {
        my $i;
        foreach my $field (@$fields) {
            if ($e eq $field) {
                $href->{$field} = 0;
                splice @$fields, $i, 0;
                print Data::Dumper->Dump([$i, $fields], [qw/i fields/]);
            }
            ++$i;
        }
    }

    print Data::Dumper->Dump([$href], [qw/href/]);
}


##</code><code>##

$ perl test.pl
$a = [
       'three',
       'one',
       'two'
     ];
$i = 3;
$fields = [
            'zero',
            'one',
            'two',
            'three',
            'four',
            'five',
            'six',
            'seven'
          ];
$i = 1;
$fields = [
            'zero',
            'one',
            'two',
            'three',
            'four',
            'five',
            'six',
            'seven'
          ];
$i = 2;
$fields = [
            'zero',
            'one',
            'two',
            'three',
            'four',
            'five',
            'six',
            'seven'
          ];
$href = {
          'three' => 0,
          'one' => 0,
          'two' => 0
        };
$