Given a binary tree, find the subtree with maximum average. Return the root of the subtree.
Example 1
Input:
{1,-5,11,1,2,4,-2}
Output:11
Explanation:
The tree is look like this:
1
/ -5 11
/ \ / 1 2 4 -2
The average of subtree of 11 is 4.3333, is the maximun.
Example 2
Input:
{1,-5,11}
Output:11
Explanation:
1
/ -5 11
The average of subtree of 1,-5,11 is 2.333,-5,11. So the subtree of 11 is the maximun.
public class Solution { private class ResType { int sum; int size; public ResType(int sum, int size) { this.sum = sum; this.size = size; } } /** * @param root: the root of binary tree * @return: the root of the maximum average of subtree */ TreeNode maxNode = null; ResType globalNode = null; public TreeNode findSubtree2(TreeNode root) { // write your code here helper(root); return maxNode; } private ResType helper(TreeNode root) { if (root == null) { return new ResType(0, 0); } ResType left = helper(root.left); ResType right = helper(root.right); int curSum = left.sum + right.sum + root.val; int curSize = left.size + right.size + 1; ResType cur = new ResType(curSum, curSize); if (maxNode == null || curSum * globalNode.size > curSize * globalNode.sum) { globalNode = cur; maxNode = root; } return cur; } }
原文地址:https://www.cnblogs.com/xuanlu/p/12419352.html
时间: 2024-10-15 06:14:16