LeetCode-108. Convert Sorted Array to Binary Search Tree(Java)

Given an array where elements are sorted in ascending order, convert it to a height balanced BST.

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题意

将按升序排列的数组转换为平衡二叉搜索树

代码

public class Solution {    public TreeNode sortedArrayToBST(int[] num) {        if (num.length == 0) {           return null;        }        TreeNode head = helper(num, 0, num.length - 1);        return head;}    public TreeNode helper(int[] num, int low, int high) {         if (low > high) { // Done           return null;        }        int mid = (low + high) / 2;        TreeNode node = new TreeNode(num[mid]);        node.left = helper(num, low, mid - 1);        node.right = helper(num, mid + 1, high);        return node;    }}