编写BP神经网络系统，可适应多节点输入输出的人工神经网络训练，即可以自由定义输入节点的个数，隐层节点个数，输出节点个数以及样本的个数。-Preparation of BP neural network system can be adapted to multi-node input and output of the artificial neural network training, that is free to define the number of input nodes, hid