884. Ceil Value in BST

Given the root of a binary search tree and a target value, return the ceil of the target — the smallest key greater 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 ceil value, or -1.

Examples

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

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

Input: [8,3,10,1,6,null,14] | 15
Output: -1
Explanation: No key >= 15.

Constraints

• 0<=nodes<=10^4
• valid BST

Asked by