Given an array where elements are sorted in ascending order, convert it to a height balanced BST.
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/** * 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) { return
transferHelper(num, 0, num.length); } /**construct tree node with the help of indices.<br> * @param num --input array * @param i --left index which is included. * @param j --right index which is excluded * @return root node of the tree */ private
TreeNode transferHelper(int[] num, int
i, int j){ TreeNode root = null; if(j > i){ if(j == i + 1) root = new
TreeNode(num[i]); else{ int
mid = i + (j - i) / 2; root = new
TreeNode(num[mid]); root.left = transferHelper(num, i, mid); root.right = transferHelper(num, mid + 1, j); } } return
root; }} |
leetcode--Convert Sorted Array to Binary Search Tree,布布扣,bubuko.com
leetcode--Convert Sorted Array to Binary Search Tree
原文：http://www.cnblogs.com/averillzheng/p/3772354.html