Use as a Tree:
Finding your parents/children
1
4
5
6
9
10
13
17
18
19
20
21
22
30
25
0
1
2
3
4
5
6
7
8
9
10
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13
14
The children of node j are at 2j+1 and 2j+2.
The parent of node j is floor((j-1)/2).