Hacker News Reader

I'm no expert in this but I suppose just like how they check for plagiarism in essays.

They usually compare submissions with other submissions, past submissions and also against similar references on the internet in case a match is found on some website.

View on HN

I guess... but there has to be something else. You can plagarize an essay, and finding that is kinda easy because you copy-paste word by word and so, it's obvious. But two programmers can have identical pieces of code without that meaning they copied each other, don't you think?

Not really; discounting extremely simple programs like print "Hello world", there are many possible stylistic differences and people will write things differently. One person will write for, another while; one i=0;j=0, another j=0;i=0; another will name variables differently; another will take two lines and make them into a procedure; one will write "if x then return y else return z", another "if x then return y; return z;", another "if not x then return z else return y" another "return x ? y : z" etc. If your assignment is at least 50 lines of code, compare it with someone else. You will see tons of differences.

Reply on news.ycombinator.com