对易阵游戏中两子交换的问题进行说明。讨论用回溯法搜索相邻两子交换的算法，进而研究任意两子交换的算法，重点研究搜索树的结构，并用类Java语言分别对其实现的最优算法进行描述。-On the trade front in the game two sons, the issue of exchange instructions. Discussions with the backtracking search algorithm two adjacent sub-exchange, and then