Given an array where elements are sorted in ascending order, convert it to a height balanced BST.
For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.
//思路还是很清晰的:就是要取中间节点作为根节点,其他的分别是左子树和右子树,递归 /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: TreeNode* sortedArrayToBST(vector<int>& nums) { TreeNode *node = createBST(nums,0,nums.size()-1); return node; } public: TreeNode* createBST(vector<int>nums, int left, int right){ if (left>right) return NULL;//?? int mid = (left+right)/2; TreeNode *node = new TreeNode(nums[mid]); node->left = createBST(nums, left, mid - 1); node->right = createBST(nums, mid+1, right); return node; } };
递归出口NULL注意,最终只是要返回根节点。
原文地址:https://www.cnblogs.com/sherry-yang/p/8407397.html
时间: 2024-10-27 12:06:48