Binary Tree Pruning
Given the root of a binary tree, return the same tree where every subtree of the given tree not containing a 1 has been removed.
A subtree of a node node is node plus every node that is a descendant of node.
Example 1
1 1
\ -> \
0 0
/ \ \
0 1 1Input
root = [1,null,0,0,1]Output
[1,null,0,null,1]Only the nodes that are part of a subtree containing a 1 remain in the returned tree.
Example 2
1 1
/ \ -> \
0 1 1
/ \ / \ \
0 0 0 1 1Input
root = [1,0,1,0,0,0,1]Output
[1,null,1,null,1]All subtrees containing only 0 values are removed, leaving the pruned tree shown in the output.
Constraints
- The number of nodes in the tree is in the range
[1, 200]. Node.valis either0or1.