Convert Sorted Array to Binary Search Tree

最新推荐文章于 2022-02-19 22:56:38 发布

原创最新推荐文章于 2022-02-19 22:56:38 发布 · 69 阅读

0 ·

CC 4.0 BY-SA版权

刷题专栏收录该内容

169 篇文章

订阅专栏

本文介绍了一种将有序数组转换为平衡二叉搜索树的方法。通过递归方式，选择中间元素作为根节点，并将左右两侧的子数组分别递归地构建为左子树和右子树。

/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
class Solution {
public TreeNode sortedArrayToBST(int[] nums) {
if(nums == null || nums.length == 0) return null;
return builder(nums, 0, nums.length - 1);
}

private TreeNode builder(int[] nums, int start, int end) {
if(start > end) {
return null;
}
int mid = start + (end - start) / 2;
TreeNode root = new TreeNode(nums[mid]);
root.left = builder(nums, start, mid - 1);
root.right = builder(nums, mid + 1, end);
return root;
}
}