* TreeNode(int x) : val(x), left(NULL), right(NULL) {} * };*/classSolution {public: TreeNode* sortedArrayToBST(vector<int>&nums) {if(nums.empty())returnnullptr;TreeNode*root = helper(nums,0, nums.size()-1);returnroot; } TreeNode*helper(vector<int>& nums,intstart,intend){if...
Main.sortedArrayToBST(num1) 验证结果: Runtime:72 ms, faster than24.34%ofPython3online submissions forConvert Sorted Array to Binary Search Tree. Memory Usage:15.4 MB, less than5.70%ofPython3online submissions forConvert Sorted Array to Binary Search Tree. 速度太慢了,看来本题优化的空间还很大,...
intstart,intend){if(start==end){returnnull;}intmid=(start+end)>>>1;TreeNoderoot=newTreeNode(nums[mid]);root.left=sortedArrayToBST(nums,start,mid);root.right=sortedArrayToBST(nums,mid+1,end);returnroot;}
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 ofeverynode never differ by more than 1. Example: Given the sorted array:...
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 ofeverynode never differ by more than 1. ...
108. Convert Sorted Array to Binary Search Tree 题目分析 给定一个顺序数组,将其装换成平衡二叉树。 思路 首先讲数组分成两半,左边的元素为左子树的内容,右边为右子树内容。 中间的元素作为当前节点的值。 若左边的元素个数大于0,则递归该进程。
Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 分析: Input:So we're given a sorted array in ascending order. **Output: ** To return the root of a Binary Search Tree. The corner case is when the input array is null or empty, then...
{returnsortedArrayToBST(nums,0,nums.size());}privateTreeNodesortedArrayToBST(ArrayList<Integer>nums,intstart,intend){if(start==end){returnnull;}intmid=(start+end)>>>1;TreeNoderoot=newTreeNode(nums.get(mid));root.left=sortedArrayToBST(nums,start,mid);root.right=sortedArrayToBST(nums,mid...
Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 递归法 复杂度 时间O(N) 空间 O(H) 思路 和用链表建树的思路相似,实现更加简单,因为数组支持随机查询,我们可以直接访问中点而无须遍历链表。
Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 本题是二分法的高级应用,每次选择root都是从数列的中间选择,那么最后构造出来的二叉树一定是高度平衡的BST了。