将有序数组转换为二叉搜索树 JavaScript

ゝ一世哀愁。 2022-05-18 08:49 189阅读 0赞

题目详细：[https://leetcode-cn.com/problems/convert-sorted-array-to-binary-search-tree/description/][https_leetcode-cn.com_problems_convert-sorted-array-to-binary-search-tree_description]

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将有序数组转化为二叉搜索树时，树根位于有序数组中间mid，mid左边的构成左子树，右边的构成右子树。  
通过递归调用，对二叉树进行构造。nums为0、1、大于1时，返回不同的结果。  
此题参考博客：[https://blog.csdn.net/romeo12334/article/details/81223669][https_blog.csdn.net_romeo12334_article_details_81223669]

/** * Definition for a binary tree node. * function TreeNode(val) { * this.val = val; * this.left = this.right = null; * } */
    /** * @param {number[]} nums * @return {TreeNode} */
    var sortedArrayToBST = function(nums) {
        if(nums.length === 0) {
            return null;
        } else if(nums.length === 1) {
            return new TreeNode(nums[0]);
        } else {
            // var mid = nums.length / 2;
            //注意此处需要用到parseInt()函数将结果转化为整数
            var mid = parseInt(nums.length / 2);
    
            var root = new TreeNode(nums[mid]);
    
            root.left =  sortedArrayToBST(nums.slice(0,mid));
            root.right =  sortedArrayToBST(nums.slice(mid+1));
            return root;
        }
    };

[https_leetcode-cn.com_problems_convert-sorted-array-to-binary-search-tree_description]: https://leetcode-cn.com/problems/convert-sorted-array-to-binary-search-tree/description/
[https_blog.csdn.net_romeo12334_article_details_81223669]: https://blog.csdn.net/romeo12334/article/details/81223669