_108.java

package com.fishercoder.solutions;

import com.fishercoder.common.classes.TreeNode;

/**
 * Given an array where elements are sorted in ascending order, convert it to a height balanced BST.
 */
public class _108 {

    public TreeNode sortedArrayToBST(int[] num) {
        return rec(num, 0, num.length - 1);
    }

    public TreeNode rec(int[] num, int low, int high) {
        if (low > high) {
            return null;
        }
        int mid = low + (high - low) / 2;
        TreeNode root = new TreeNode(num[mid]);
        root.left = rec(num, low, mid - 1);
        root.right = rec(num, mid + 1, high);
        return root;
    }

}