Exactly three adjacent 3 in lists: Difference between revisions

=={{header|Perl}}==

<lang perl>#!/usr/bin/perl

use strict; # https://rosettacode.org/wiki/Exactly_three_adjacent_3_in_lists

use warnings;

my @lists = (

[9,3,3,3,2,1,7,8,5],

[5,2,9,3,3,7,8,4,1],

[1,4,3,6,7,3,8,3,2],

[1,2,3,4,5,6,7,8,9],

[4,6,8,7,2,3,3,3,1]);

for my $ref ( @lists )

{

my @n = grep $ref->[$_] == 3, 0 .. $#$ref;

print "@$ref => ",

@n == 3 && $n[0] == $n[1] - 1 && $n[1] == $n[2] - 1 ? 'true' : 'false',

"\n";

}</lang>

{{out}}

<pre>

9 3 3 3 2 1 7 8 5 => true

5 2 9 3 3 7 8 4 1 => false

1 4 3 6 7 3 8 3 2 => false

1 2 3 4 5 6 7 8 9 => false

4 6 8 7 2 3 3 3 1 => true

</pre>