add document for algorithm
add document for algorithm

Yexiaoxing/CUHKSZLib,alesiong/CUHKSZLib,cuhkshenzhen/CUHKSZLib,alesiong/CUHKSZLib,cuhkshenzhen/CUHKSZLib,Yexiaoxing/CUHKSZLib,alesiong/CUHKSZLib,Yexiaoxing/CUHKSZLib,cuhkshenzhen/CUHKSZLib