# File:		tr2.pl
# Author:	Jason L. Bryant
# Title:	Makes a string of characters from an alphabet, and counts 
#		    the occurences of each letter (counting with tr). To Improve!
#	Alphabet = a c g t
#	Length of string? 5
#	Generated String is acgaat
#	Occurrences of A= 3
#	Occurrences of C= 1
#	Occurrences of G= 1
#	Occurrences of T= 1
@Alpha = ('a','c','g','t');
print "Alphabet is @Alphabet";
print "Length of string)? ";
$n = <STDIN>; chop($n);
$s = '';						# initialize final string s with empty ''
for ( 1..$n ) {
	$pos = int rand(4);			# generates random integer < 4
	$s = $s . $Alpha[$pos];		# concatenation with .
}	
print "Generated string is $S\n"; 
$_ = $s;
$Ka = tr/a/a/;			#counts how many a's
$Kc = tr/c/c/;			#counts how many c's
$Kg = tr/g/g/;			#counts how many g's
$Kt = tr/t/t/;			#counts t
print "Occurrences of A= $Ka\nOccurrences of C= $Kc\n";
print "Occurrences of G= $Kg\nOccurrences of T= $Kt\n";
exit;