Originally Posted by

**MagiMaster**
I mean a test case where there's only one right answer consisting of one N/2 length subset. The only one right answer part makes it hard to solve (and also hard to construct).

One possibility would be to take all the numbers from 1 to 5,000, which total 12,502,500 (which would be the target), and then another 5000 numbers greater than that, but it might not be too hard to throw away such numbers since there are no negative numbers to balance them out. If you do add in some negative numbers, you'd have to make sure that they couldn't be used as part of the solution. I suppose you could take random (positive and negative) multiples of something like 20,000,000, but then you wouldn't have all unique numbers since there are only about 200 such numbers that would fit in a 32-bit integer.