说明：  petri网络的演示程序源码，本程序源码是计算机网络课程中涉及到的petri网络络的演示，输入预先的转换规则，搜索能击发的状态，设定次数进行状态转换 可直接使用。
(Petri network demo program source code, the program source code is a computer network courses related to petri network network presentations, enter the pre-conversion rules, the search can be firing state, set the number of state transitions can be used directly.)