Bitboard Connection Code Design for Connect6

This paper follows the results of our previous work. In our previous work, we encode the shape of a Connection with its length, and it is named pattern index. The pattern index is used to identify the variety of stone arrangements of a Connection, therefore, it can be used to retrieve information from shape information table. In this study, we further proposed an encoding method of a Connection based on the concept of encoding pattern index, and it is named Connection Code. Connection Code can be used to identify a Connection, which may appear on Board. In the study, a variable with 32 bits is used to encode Connection Code, and it includes four key attributes of a Connection: stone color, line index of Board, start index of the line, and pattern index. Besides, the related bitwise computing is provided to retrieve information and to handle the Connection Code. When we need related information of the Connection, these bitwise computing can be used to get it.