A new approach to compute deficiency number of Mahjong configurations.

Mahjong is a traditional Chinese tile-based game with long history, and now it is world-widely played in many different countries. An important issue on Mahjong topic is how many tiles the player needs to change minimally for the winning, i.e., the so-called deficiency number, which plays a significant role in AI development for Mahjong game. However, deficiency number cannot be easily computed due to a large amount of possible combinations of tiles. In this work, we propose an efficient algorithmic approach to compute the deficiency number of the tiles in players' hands with the assistance of the programming language Python. In order to evaluate the performance of the approach, we established more than 1.2 million test cases for various deficiency numbers. Finally, the experimental results show the efficiency of our approach.