# File:	count2.pl
# Title: 	Asks for a string (DNA string). Alphabet is acgt
#		    Count the occurrences of all letters in the give alphabet in the string
# Author:	Mihaela Malita
#		What string? acgtacgataga
#		Occurences of a = 5
#		Occurences of c = 2
#		Occurences of g = 3
#		Occurences of t = 2
print "What string? ";
$S = <STDIN>;	 chop($S);
$count_a = 0;			# initialize counter
$count_c = 0;			# initialize counter
$count_g = 0;			# initialize counter
$count_t = 0;			# initialize counter
@S = split('', $S); 		# transforms string in array
foreach $i ( @S ) {		# for every element in array
	if ($i eq 'a'){ ++$count_a };     # increments counter $count_a
	if ($i eq 'g'){ ++$count_g };     # increments counter $count_g
	if ($i eq 'c'){ ++$count_c };     # increments counter $count_c
	if ($i eq 't'){ ++$count_t };     # increments counter $count_t
}
print  "\nOccurences of a = $count_a";
print  "\nOccurences of c = $count_c";
print  "\nOccurences of g = $count_g";
print  "\nOccurences of t = $count_t";
exit;