LeetCode Convert Sorted Array to Binary Search Tree

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

题意：将一个有序数组变成二叉搜索树。

思路：简单的递归。

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    private TreeNode build(int[] nums, int start, int end) {
		if (start > end) return null;
		int mid = start + end >> 1;
		TreeNode root = new TreeNode(nums[mid]);
		root.left = build(nums, start, mid-1);
		root.right = build(nums, mid+1, end);
		return root;
	} 
	
    public TreeNode sortedArrayToBST(int[] nums) {
    	return build(nums, 0, nums.length-1);
    }
}

LeetCode Convert Sorted Array to Binary Search Tree

原文：http://blog.csdn.net/u011345136/article/details/45506833