You are given the root of a binary tree. We install cameras on the tree nodes where each camera at a node can monitor its parent, itself, and its immediate children. Return the minimum number of cameras needed to monitor all nodes of the tree.
Java
Binary Tree Cameras
You are given the root of a binary tree. We install cameras on the tree nodes where each camera at a node can monitor its parent, itself, and its immediate children. Return the minimum number of cameras needed to monitor all nodes of the tree.
Example 1:
Input: {"root":[0,0,null,0,0]}
Output: 1
Input
arr ={"root":[0,0,null,0,0]}
Install minimum cameras to monitor all nodes. States: 0=not covered, 1=covered, 2=has camera