Gene Representation

• You have to solve the problem by a gene representation.
• That representation is a string of elements of a relatively small alphabet.
• In biology it's 4 letters (AGCT?).
• In simulations it's typically done with digits, binary, or letters.
• How would you represent a travelling salesman problem with 20 cities?
• It might be a string of 20 numbers between 1 and 20. You'd like the numbers to be non-repeating.
• How many possible solutions are there?
• How many total solutions (including the invalid ones) are there?