Q8

A rooted tree with $12$ nodes has its nodes numbered $1$ to $12$ in pre-order. When the tree is traversed in post-order, the nodes are visited in the order $3, 5, 4, 2, 7, 8, 6, 10, 11, 12, 9, 1$. Reconstruct the original tree from this information, that is, find the parent of each node, and show the tree diagrammatically.