标签：put solution input sub out between val bsp integer
Given a binary tree, return the tilt of the whole tree.
The tilt of a tree node is defined as the absolute difference between the sum of all left subtree node values and the sum of all right subtree node values. Null node has tilt 0.
The tilt of the whole tree is defined as the sum of all nodes‘ tilt.
Example:
Input:
1
/ 2 3
Output: 1
Explanation:
Tilt of node 2 : 0
Tilt of node 3 : 0
Tilt of node 1 : |2-3| = 1
Tilt of binary tree : 0 + 0 + 1 = 1
Note:
1 /** 2 * Definition for a binary tree node. 3 * public class TreeNode { 4 * int val; 5 * TreeNode left; 6 * TreeNode right; 7 * TreeNode(int x) { val = x; } 8 * } 9 */ 10 public class Solution { 11 public int findTilt(TreeNode root) { 12 if (root == null) return 0; 13 if (root.left == null && root.right == null) return 0; 14 15 int myTilt = findNodeTilt(root); 16 return myTilt + findTilt(root.left) + findTilt(root.right); 17 } 18 19 public int findNodeTilt(TreeNode root) { 20 if (root == null) return 0; 21 if (root.left == null && root.right == null) return 0; 22 int leftSum = subtreeSum(root.left); 23 int rightSum = subtreeSum(root.right); 24 25 return Math.abs(leftSum - rightSum); 26 } 27 28 private int subtreeSum(TreeNode root) { 29 if (root == null) return 0; 30 if (root.left == null && root.right == null) return root.val; 31 32 return root.val + subtreeSum(root.left) + subtreeSum(root.right); 33 } 34 }
标签：put solution input sub out between val bsp integer
原文地址：http://www.cnblogs.com/amazingzoe/p/6791732.html
