Leetcode Solutions Java Python C++
All contents and pictures on this website come from the Internet and are updated regularly every week. They are for personal study and research only, and should not be used for commercial purposes. Thank you for your cooperation.
Welcome to Subscribe On Youtube:

968. Binary Tree Cameras

Given a binary tree, we install cameras on the nodes of the tree. 

Each camera at a node can monitor its parent, itself, and its immediate children.

Calculate the minimum number of cameras needed to monitor all nodes of the tree.

 

Example 1:

Input: [0,0,null,0,0]
Output: 1
Explanation: One camera is enough to monitor all nodes if placed as shown.

Example 2:

Input: [0,0,null,0,null,0,null,null,0]
Output: 2
Explanation: At least two cameras are needed to monitor all nodes of the tree. The above image shows one of the valid configurations of camera placement.


Note:

  1. The number of nodes in the given tree will be in the range [1, 1000].
  2. Every node has value 0.

Difficulty:

Hard

Lock:

Normal

Company:

Facebook Google

Problem Solution

968-Binary-Tree-Cameras

All Problems:

Link to All Problems
All contents and pictures on this website come from the Internet and are updated regularly every week. They are for personal study and research only, and should not be used for commercial purposes. Thank you for your cooperation.