This seems similar to selecting a single random line from a file in a single pass: http://41j.com/blog/2015/02/select-random-line-file-single-pass/ http://41j.

This seems similar to selecting a single random line from a file in a single pass: http://41j.com/blog/2015/02/select-random-line-file-single-pass/ http://41j.com/blog/2015/02/select-random-line-file-single-p... Which is a question I've had come up in interviews. It's a neat trick.