如何将文本文件读入数组数组（每个子数组是文本文件中的一行？）

so I'm pretty much a n00b at Ruby, and I've put together a code to solve a MinCut problem (for an assignment, yes - that part of the code I've put together and tested), and I can't figure out how to read a file and put it into an array of arrays. I have a text file to read, with columns of varying length as belowso I'm pretty much a n00b at Ruby, and I've put