my @arrayC;
while(defined($textblock) = <>) {
    my @arrayA = ();
    foreach my $string (@strings) {
        my @arrayB = ();
            while($textblock =~ /$string/) {
                push @arrayB, [ $-[0], $+[0] ];
        }
        push @arrayA, \@arrayB;
    }
    push @arrayC, \@arrayA;
}