Решение

class Solution {
    fun sortedArrayToBST(nums: IntArray): TreeNode? {
        fun build(l: Int, r: Int): TreeNode? {
            if (l > r) return null
            val m = (l + r) ushr 1
            val node = TreeNode(nums[m])
            node.left = build(l, m - 1)
            node.right = build(m + 1, r)
            return node
        }
        return build(0, nums.size - 1)
    }
}