Binary Tree Cameras
You are given the root of a binary tree. You may install cameras on nodes, where each camera monitors:
- The node on which it is installed.
- Its parent.
- Its immediate left and right children.
Your task is to determine the minimum number of cameras required so that every node in the binary tree is monitored.
Return the minimum number of cameras needed.
Examples
Input: root = [0,0,null,0,0]
Output: 1
Explanation: A single camera placed on the second node can monitor all nodes in the tree.
Input: root = [0,0,null,0,null,0,null,null,0]
Output: 2
Explanation: At least two cameras are required to monitor every node in this skewed tree.
Input: root = [0]
Output: 1
Explanation: A single node needs one camera to be monitored.
Constraints
- 1 = Number of nodes = 1000
- -10? = Node.data = 10?
Companies
Topics
Solution.cs C#JavaPythonC++Javascript
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