Given the root
of a binary tree, each node in the tree has a distinct value.
After deleting all nodes with a value in to_delete
, we are left with a forest (a disjoint union of trees).
Return the roots of the trees in the remaining forest. You may return the result in any order.
Example 1:
1
/ \
/ \
2 3
/ \ / \
4 5 6 7
Input: root = [1,2,3,4,5,6,7], to_delete = [3,5]
Output: [[1,2,null,4],[6],[7]]
Example 2:
Input: root = [1,2,4,null,3], to_delete = [3]
Output: [[1,2,4]]
Constraints:
 The number of nodes in the given tree is at most
1000
.  Each node has a distinct value between
1
and1000
. to_delete.length <= 1000
to_delete
contains distinct values between1
and1000
.

