题目

图片.png

题解

  1. class Solution {
  2. public:
  3.     TreeNode* sortedArrayToBST(vector<int>& nums) {
  4.         return helper(nums, 0, nums.size()-1);
  5.     }
  7.     TreeNode* helper(vector<int>& nums, int left, int right) {
  8.         if (left > right) {
  9.             return nullptr;
  10.         }
  12.         //中序递归创建二叉树
  13.         int mid = (left + right) / 2; //每次取中间或者中间的左边为根节点
  14.         TreeNode* root = new TreeNode(nums[mid]);
  15.         root->left = helper(nums, left, mid - 1);
  16.         root->right = helper(nums, mid + 1, right);
  17.         return root;
  18.     }
  19. };