Pointer-based Binary Heaps

Hi, I this is my StackOverflow answer about pointer-based binary heaps.

My current (quite optimized) implementation of the discussed hybrid approach is here [1]. Due to the "pointer abstraction" which I use, it is somehow harder to understand at first, so to see how to wire it together examine the test program [2].

[1] https://github.com/ambrop72/aprinter/blob/ipstack/aprinter/s...

[2] https://github.com/ambrop72/aprinter/blob/ipstack/tests/link...