Had some issues implementing the heap, and then realised had a nice Access Violation (didn't bother to check we weren't exceeding the bounds on the heaps underlying array).

Now I'm stuck on Test #8 - but I've tried every test I've seen suggested in the comments....Anyone got a nice test to try ???

I've even tried generating up to about 190000 random numbers < 2^31-1 in Excel (3 columns) and my median always agrees with theirs....

I've Also tried the same number of ordered numbers (incrementing by 1) as well as random but sorted numbers in a single column (sorted in both directions).

I suspect I have some silly output issue (rather than a logic issue - but that might just be because I;m arrogant).

Ok, for those who have trouble with test 8.  Apparently 0 is a valid value in the tests (I'd assumed that POSITIVE meant "strictly greater than 0" - I would have thought including 0 is NON-NEGATIVE rather than POSITIVE).  Once I catered for the possibility of 0 in the heap, everything was happy....

In my case I was getting wrong one of the elements for the semi-sum.