In the spirit of TIMTOWTDI, here's a pointless regex version. But if this indeed IS homework, turning this in will certainly impress your teacher.

#!/usr/bin/perl

use strict;
use warnings;

my $line1 = 'asdadAADSAsdfsfASASDjljsdASDAS';
my $line2 = 'GKHSKJADHasdadhkadhGHKJHKJHasdada';

for my $word( $line1, $line2 ){
  print "Before: $word\n After: ";
  $word =~ /((\w)\W*(?{ ord $2 > 96 })(?{ print $^R ? uc $2 : lc $2 })
+)+/;
  print "\n\n";
}
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Output:

Before: asdadAADSAsdfsfASASDjljsdASDAS
 After: ASDADaadsaSDFSFasasdJLJSDasdas

Before: GKHSKJADHasdadhkadhGHKJHKJHasdada
 After: gkhskjadhASDADHKADHghkjhkjhASDADA
[download]

$,=42;for(34,0,-3,9,-11,11,-17,7,-5){$*.=pack'c'=>$,+=$_}for(reverse s
+plit//=>$*
){$%++?$ %%2?push@C,$_,$":push@c,$_,$":(push@C,$_,$")&&push@c,$"}$C[$#
+C]=$/;($#C
>$#c)?($ c=\@C)&&($ C=\@c):($ c=\@c)&&($C=\@C);$%=$|;for(@$c){print$_^
+$$C[$%++]}
[download]