Combinatorial problem optimization requires a new type of data representation.  Consider the example of ordering shops on the list.  We could write our route as a sequence of numbers, with each number representing a particular point.  If we are visiting five shops, we can number all of them and represent valid sequences in the form:

3-4-1-2-5   1-3-2-4-5   3-5-1-2-4, etc.

The first string means that we will visit shop #3, followed by shop #4, and so on.

Two parameters are used to describe these strings:  the number of points and the length of the string.  Note that these two parameters are not always equal.  The difference has to do with how the numbers in the string are represented.  The different methods will be discussed in the following paragraphs.

Length of Continuous Chromosomes

Length of Enumerated Chromosomes