Think about a company like Amazon and the common "Customers who purchased X also purchased y" feature. If Amazon were to create a classification tree, how many branches and nodes could it have?

举个例子，亚马逊这样的公司常常使用“购买了X的顾客还购买了Y ”特性，如果亚马逊拟创建一个分类树，那么它将需要多少分支和节点？

youdao

It's classic Amazon: unostentatious, and no company signs on any of the buildings.

这就是经典的亚马逊：朴素而不声张，在楼上没有任何公司的标识。

youdao

Today, the world's largest bookseller, Amazon, is a software company—its core capability is its amazing software engine for selling virtually everything online, no retail stores necessary.

今日世界最大的书上亚马逊是一家软件公司，它的核心能力就是自己为在线销售一切所作的超强的软件引擎。 零售店没有必要了。

youdao

IMDb, an Amazon company for 14 years, is the world's most popular and authoritative source for movie, TV and celebrity content, with more than 160 million monthly unique visitors worldwide.

ENGADGET: Amazon intros X-Ray for TV, helps you remember those 'Game of Thrones' actors

LONDON--June 25, 2012--LOVEFiLM, an Amazon Company, and Twentieth Century Fox Television Distribution have today announced a major multi-year content deal giving LOVEFiLM members streaming access to recent and forthcoming movies and TV series.

ENGADGET: Lovefilm, Fox UK deal brings more TV shows next month, movie exclusives in 2013

Monday February 11, 2013 -- LOVEFiLM, an Amazon company, will bring even more celebrated content from BBC Worldwide's impressive catalogue of shows to its members in 2013 after announcing it is rebooting its content deal with the global distributor today.

ENGADGET: Amazon to spice up Lovefilm with BBC and original content, serve it to Bravias in HD