Class Tree  

Description 
This problem has its roots in Bioinformatics and Coding Theory. Problem: find as large a set S of strings (words) of length 8 over the alphabet W = { A,C,G,T } with the following properties: c1. Each word in S has 4 symbols from { C,G }; c2. Each pair of distinct words in S differ in at least 4 positions; and c3. Each pair of words x and y in S (where x and y may be identical) are such that xR and yC differ in at least 4 positions. Here, ( x1,…,x8 )R = ( x8,…,x1 ) is the reverse of ( x1,…,x8 ) and ( y1,…,y8 )C is the WatsonCrick complement of ( y1,…,y8 ), i.e. the word where each A is replaced by a T and vice versa and each C is replaced by a G and vice versa. we modeled this problem as decisional problem increasing the number of words to obtain optimal solution. author: Davide Micaletto. 
Encodings 1  3 of 3 
