该程序用BP神经网络解决XOR问题，其中设置了恒定权值、阈值和随机权值、阈值；并且将梯度下降法进行添加记忆一项来改进。(Using BP neural network to solve XOR problem, the program which set up a constant weight and threshold and random weight and threshold value;And the gradient descent method to add a to impro