树 - Convert Sorted Array to Binary Search Tree

一，Convert Sorted Array to Binary Search Tree

题目描述

Given an array where elements are sorted in ascending order, convert it to a height balanced BST.

我的代码

/**
 * 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) {
        return dfs(nums, 0, nums.size()-1);
    }

    TreeNode* dfs(vector<int>& nums, int low, int high){
        if(low > high){
            return NULL;
        }
        int mid = (low + high) / 2;
        TreeNode *p = new TreeNode(nums[mid]);
        p->left = dfs(nums, low, mid - 1);
        p->right = dfs(nums, mid + 1, high);
        return p;
    }
};