perl - minimum number of character deletions (of both) required to turn these strings into anagrams? -

two strings given,how many minimum number of character deletions (of both) required turn these strings anagrams. constraint: need use single hash

aaabbc abc

output - 3 ( 2 , 1 b)

i able achieve using 2 hashes , tried below solution using 1 hash -

my $str1 = 'aaabbc'; $str2 = 'abc';  %h;  map{$h{$_}++} sort(//,$str1); map{$h{$_}++} sort(//,$str2);  $c = 0;  foreach (keys(%h)) {     if($h{$_} == 1) {         $c++;     } }  print "$c\n"; 

it fail in many case ('xxx', 'yyy'). suggestions?

to use single hash (smells homework) increment count characters in first string , decrement characters in second string. equal numbers of same character cancel out. non-zero values remain magnitude of difference, take absolute value when tallying total number of differences.

my $str1 = 'aaabbc'; $str2 = 'abc'; %h; $c;  $h{$_}++ foreach split //, $str1; $h{$_}-- foreach split //, $str2;  $c += abs($_) foreach values %h;  print $c;