Tracing upward from 19, the sequence of ancestors encountered before reaching the root 10 is:
\(19 \rightarrow 20 \rightarrow 30 \rightarrow 15 \rightarrow 10\)
This traversal involves four parent-child connections.
Hence, the distance from node 19 to the root is \(\boxed{4}\).
Let 𝑛 be an odd number greater than 100. Consider a binary minheap with
𝑛 elements stored in an array 𝑃 whose index starts from 1.
Which of the following indices of 𝑃 do/does NOT correspond to any leaf node of
the minheap?