lstm是怎么解决梯度消失问题的
https://www.quora.com/How-does-LSTM-help-prevent-the-vanishing-and-exploding-gradient-problem-in-a-recurrent-neural-network#:~:text=The%20vanishing%20(and%20exploding)%20gradient%20problem%20is%20caused%20by%20the,controlled%20by%20the%20forget%20gat