A data processing algorithm problem

There is a data of 50 million users, and there is a record of 200 million users watching movies. With only 1G of memory, find the top 1000 users who watch the most movies?

What should I do?

 

Guess you like

Origin http://43.154.161.224:23101/article/api/json?id=324742840&siteId=291194637