A lot of folks seem to believe that this fundamentally screws over the professor. If it does, he's an idiot, and I speak as someone intimately involved with all this before.
There are basically three kinds of CS assignments. The first is the moral equivalent of algebra problems, where you change the parameters every year if you care. These were boring to give, boring to solve, but very easy to grade.
The second is "write an implementation of X" for X ranging over things like binary trees, etc. In these cases there is one correct answer that the TA is looking for and it is already in the book. No creativity is necessary. Simple copy/paste detection will catch obvious cheaters, and anybody who modifies this guy's code enough to be non-obvious has just performed as much work, if not more, than was needed to do the assignment in the first place.
The third assignment requires creativity, and here if two students solve the problem in the same way you can usually be sure they colluded. Most of these can be trivially changed, but they're a bitch to grade (although my favorite problems on both sides of the aisle, they're very time consuming) and so are not favored by lazy profs.
There are basically three kinds of CS assignments. The first is the moral equivalent of algebra problems, where you change the parameters every year if you care. These were boring to give, boring to solve, but very easy to grade.
The second is "write an implementation of X" for X ranging over things like binary trees, etc. In these cases there is one correct answer that the TA is looking for and it is already in the book. No creativity is necessary. Simple copy/paste detection will catch obvious cheaters, and anybody who modifies this guy's code enough to be non-obvious has just performed as much work, if not more, than was needed to do the assignment in the first place.
The third assignment requires creativity, and here if two students solve the problem in the same way you can usually be sure they colluded. Most of these can be trivially changed, but they're a bitch to grade (although my favorite problems on both sides of the aisle, they're very time consuming) and so are not favored by lazy profs.