获取权重
https://blog.csdn.net/shwan_ma/article/details/78874881
https://blog.csdn.net/u013243986/article/details/77333887
https://blog.csdn.net/AManFromEarth/article/details/81057577
https://blog.csdn.net/LEILEI18A/article/details/80032577
https://zhuanlan.zhihu.com/p/31308381