The obvious way:

#! perl -slw
use strict;

my $dna = do{ local $/; <DATA> };
$dna =~ tr[\n][]d;

my %counts;
++$counts{ substr $dna, $_, 1 } for 0 .. 199;

for my $offset ( 0 .. length( $dna )-200 ) {
    printf "range: %d .. %d A:%d C:%d G:%d T:%d\n", $offset, $offset+1
+99, @counts{ qw[ A C G T ] };
    --$counts{ substr $dna, $offset, 1 };
    ++$counts{ substr $dna, $offset+200, 1 };
}

__DATA__
TGCCATCGCGCCAGGAGGGAAGACCAGTTGCTCTGGGTAAATCAGCCGTGAGCGTATCTGTCCCTCTTAT
+AATTAGGAGTTTAAACTCTACGATGTTACC
ATCCTTGAATCAGGTATATACCGCACTGAAACATCGTCGGCTTTGGGCTCATTCGCTACCCTGTCGCTGA
+TATGCGATCTATTCTACATATGCGGGGCCA
CCCAATGTCGATTGTCATGAGGAGGGGGTCATAACGACTCACTATAGGACCAGCACGTCCGGTTGCGCTG
+AGTAAAATAGAGCTACAAAAGACACAGTAC
TCCAAGATGTAAAGGGGAAGACGGGACCTGGGTCGGGGGCGCAACTTCACTGAGCTTTTAACCTTGCGCG
+CATGCGAGAGCCTTTCCGCTTAGGAAATGC
TGTAAGATCAAGTGGTAGGACTATTGAGAGGTCTTACCTTGCCGCAGCAACGTGGACGGCGACCGGATAA
+TTTAAGGCCGACATTCAATATAGAATGTCA
GGGAGCAGAACTGTATCCCAAATGCTAGTTGTAGGTGTACGAGCGCACCTGGGGACCTATCGCTCCGACG
+GGGTCTGCGTAGCCCATACATCCTGCCAGC
ACTGGGGCTATTGAACGGTCAATCCGTAATGTACTCGCTGAATGCTCAGGGATTCCTTAATCTTTGAGCA
+CGCGGCTTCTCTCACTTTTCTCACGTCAAC
CCTGACTCATAACGGAGTTCGGCAGTCCCGGAACGGCTTATAGAAGCAATGCCTGAGTAGATAGCGTCAG
+GGATCGGCCCTACGTCGAGTCCAGTACGCC
ATTGGATGGAGGTCTCAGCCGTCGGTGGAGTGCGGCTCCACCCCCACATGAACGAGGTTGTTCCTGACCA
+CCCCTGAAACTGTGAGAACCATTGTGTCGA
AACCAAGAGGCTTGCGTCGCGCTATAGGTCGATTGCCCCCTAGTTTCCCTATATTGAACGTGTTTCCATT
+AAAGACTCTCGGTAAATCTCACGTATTGCA

[download]

Produces:

C:\test>junk77
range: 0 .. 199 A:46 C:51 G:47 T:56
range: 1 .. 200 A:46 C:52 G:47 T:55
range: 2 .. 201 A:46 C:53 G:46 T:55
range: 3 .. 202 A:46 C:53 G:46 T:55
range: 4 .. 203 A:47 C:52 G:46 T:55
range: 5 .. 204 A:47 C:52 G:46 T:55
range: 6 .. 205 A:47 C:52 G:46 T:55
range: 7 .. 206 A:47 C:51 G:47 T:55
range: 8 .. 207 A:47 C:51 G:46 T:56
range: 9 .. 208 A:47 C:51 G:46 T:56
range: 10 .. 209 A:47 C:51 G:46 T:56
range: 11 .. 210 A:48 C:50 G:46 T:56
range: 12 .. 211 A:48 C:49 G:46 T:57
range: 13 .. 212 A:47 C:49 G:46 T:58
range: 14 .. 213 A:47 C:49 G:46 T:58
range: 15 .. 214 A:47 C:49 G:45 T:59
range: 16 .. 215 A:46 C:50 G:45 T:59
range: 17 .. 216 A:47 C:50 G:44 T:59
...

[download]
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re: how to access elements in perl by BrowserUk
in thread how to access elements in perl by grewal7634

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