883. Floor Value in BST

Given the root of a binary search tree and a target value, return the floor of the target — the largest key less than or equal to the target. Return -1 if no such key exists. The input gives a level-order BST array and the target separated by ' | '.

Input: A level-order BST array and the target, separated by ' | '.

Output: Integer — the floor value, or -1.

Examples

Input: [8,3,10,1,6,null,14] | 5
Output: 3
Explanation: Largest key <= 5.

Input: [8,3,10,1,6,null,14] | 6
Output: 6
Explanation: Exact match is its own floor.

Input: [8,3,10,1,6,null,14] | 0
Output: -1
Explanation: No key <= 0.

Constraints

• 0<=nodes<=10^4
• valid BST

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