Lab 14, Task 1
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1. The node with a key of 27.

2. Its left child will be in position  2*4 + 1 = 9
   Its right child will be in position 2*4 + 2 = 10
   Its parent will be in position (4 - 1)/2 = 1

3. The item at the top of the heap (the one with a key of 45) will be removed.
   The last item in the array (the one with a key of 5) will replace it and
   be sifted down. See the separate image file for the final result.

4 and 5. See separate images.