Good morning! Here's your coding interview problem for today.
This question was asked by BufferBox.
Given a binary tree where all nodes are either 0 or 1, prune the tree so that subtrees containing all 0s are removed.
For example, given the following tree:
0
/
1 0
/
1 0
/
0 0
should be pruned to:
0
/
1 0
/
1
We do not remove the tree at the root or its left child because it still has a 1 as a descendant.