(java) Convert Sorted Array to Binary Search Tree

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

思路:建立一个平衡的二叉搜索树，我们可以以中位数为根，比它小的的是它的左子树，比它大的是它的右子树，将左右子树已同样的方法进行下去，直到左右均没有节点为止

代码如下(已通过leetcode)

public class Solution {

public TreeNode sortedArrayToBST(int[] nums) {

if(nums.length==0) return null;

TreeNode root=createAVLBST(0,nums.length-1,nums);

return root;

}

private TreeNode createAVLBST(int low, int high, int[] nums) {

// TODO Auto-generated method stub

if(low==high) return new TreeNode(nums[low]);

else {

if(low>high) return null;

else{

int mid=(low+high)/2;

TreeNode temp=new TreeNode(nums[mid]);

temp.left=createAVLBST(low, mid-1, nums);

temp.right=createAVLBST(mid+1, high, nums);

return temp;

}

}

}

}