use strict;
use warnings;
my @arr1 = 'a' .. 'j';

my @al = (
    # Arr1  Arr2
    [  3,     4  ], 
    [  5,     5  ], 
    [  6,     6  ], 
    [  8,    10  ], 
);
my $start = 0;
my $end = 0;

for my $i (0 .. $#al) {
    $end = $al[$i][0]-1;
    print @arr1[$start .. $end], "\n";
    $start = $end+1;
}

##</code><code>##

abc
de
f
gh