Closest Binary Search Tree Value

Description

null

Solution(javascript)

/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @param {number} target
 * @return {number}
 */
const closestValue = function (root, target) {
  const aux = (node, min, result) => {
    if (!node) {
      return result
    }
    const { val } = node
    if (val > target) {
      if (val - target < min) {
        min = val - target
        result = val
      }
      return aux(node.left, min, result)
    }
    if (target - val < min) {
      min = target - val
      result = val
    }
    return aux(node.right, min, result)
  }
  return aux(root, Infinity, 0)
}