Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.
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public class Solution { /** Convert the linked list to arrayList first, and then convert the ArrayList to a BST * @param head --head node of the linked list * @return TreeNode --the root node of a height balanced BST tree * @author Averill Zheng * @version 2014-06-05 * @since JDK 1.7 */ public
TreeNode sortedListToBST(ListNode head) { TreeNode root = null; ArrayList<Integer> number = new
ArrayList<Integer>(); int
length = 0; while(head != null){ number.add(head.val); head = head.next; ++length; } root = convertHelper(number, 0, length); return
root; } private
TreeNode convertHelper(ArrayList<Integer> number, int
i, int j){ TreeNode root = null; if(j > i){ if(j == i + 1) root = new
TreeNode(number.get(i)); else{ int
mid = i + (j - i) / 2; root = new
TreeNode(number.get(mid)); root.left = convertHelper(number,i, mid); root.right = convertHelper(number, mid + 1, j); } } return
root; }} |
leetcode--Convert Sorted List to Binary Search Tree,布布扣,bubuko.com
leetcode--Convert Sorted List to Binary Search Tree
原文地址：http://www.cnblogs.com/averillzheng/p/3773662.html
