/**
* Definition for binary tree
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public TreeNode sortedArrayToBST(int[] num) {
if(num.length<=0) return null;
TreeNode root=sort(num,0,num.length-1);
return root;
}
public TreeNode sort(int[] num,int i,int j)
{
if(i>j) return null;
if(i==j)
{
return new TreeNode(num[i]);
}
int mid=(i+j)>>1;
TreeNode root=new TreeNode(num[mid]);
root.left=sort(num,i,mid-1);
root.right=sort(num,mid+1,j);
return root;
}
}