Amount of Time for Binary Tree to Be Infected
You are given the root of a binary tree with unique values, and an integer start. At minute 0, an infection starts from the node with value start.
Each minute, a node becomes infected if:
- The node is currently uninfected.
- The node is adjacent to an infected node.
Return the number of minutes needed for the entire tree to be infected.
Example 1
1
/ \
5 3
\ / \
4 10 6
/ \
9 2Input
root = [1,5,3,null,4,10,6,9,2], start = 3Output
4It takes 4 minutes for the infection to spread from node 3 to every node in the tree.
Example 2
1
Input
root = [1], start = 1Output
0At minute 0, the only node in the tree is infected so we return 0.
Constraints
- The number of nodes in the tree is in the range [1, 10^5].
- 1 <= Node.val <= 10^5
- Each node has a unique value.
- A node with a value of start exists in the tree.