设计一个简单的下棋游戏，游戏的规则是：在3 3的棋盘上，计算机为一方，人为一方，交替标记叉（X）和圆圈（O）。在行、列、对角线的方向上，先连成一条直线的一方为胜者。计算机可以动态地显示棋盘，给出提示信息和胜负判断，并允许用户选择是先手还是后手。-Design a simple chess game rules of the game are: In the 3 　3 of the board, the computer on the one hand, man-made side, alternating mark fork (X) and circles (O). Line, column, diagonal direction, even into a straight line before the party the winner. Computer can dynamically display board, give tips and winning judgments, and allows the user to choose the upper hand, or flac.