题目: Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. For example:Given binary tree, 5 / \ 1 5 / \ \ 5 5 5 return 4. 链接: http://leetcode.com/problems/count-univalue-su…

Problem: Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. For example:Given binary tree, 5 / \ 1 5 / \ \ 5 5 5 return 4. Analysis: This problem is super simple. But,…

Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. Example : Input: root = [5,1,5,5,5,null,5] 5 / \ 1 5 / \ \ 5 5 5 Output: 4 题意: 给定一棵二叉树,求所有节点都同值的二叉树. 思路: dfs 代码: clas…

Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. For example:Given binary tree, 5 / \ 1 5 / \ \ 5 5 5 return 4. 给一个二叉树,求唯一值子树的个数.唯一值子树的所有节点具有相同值. 解法:递归 Java: /** * De…

Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. Example : Input: root = [5,1,5,5,5,null,5] 5 / \ 1 5 / \ \ 5 5 5 Output: 4 /** * Definition for a binary tree node. *…

Count Univalue Subtrees Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. For example:Given binary tree, 5 / \ 1 5 / \ \ 5 5 5 return 4. 分析: 有点像自低向上的动态规划,既然是自底向上,看来用递归…

Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. For example:Given binary tree, 5 / \ 1 5 / \ \ 5 5 5 return 4. 这道题让我们求相同值子树的个数,就是所有节点值都相同的子树的个数,之前有道求最大BST子树的题Largest…

Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. For example:Given binary tree, 5 / \ 1 5 / \ \ 5 5 5 return 4. 给定一个二叉树,计算单值子树的数目. 单值子树意味着子树的所有节点都具有相同的值. 例如: 给定二叉树, 5…

Given a binary tree, count the number of uni-value subtrees. A Uni-value subtree means all nodes of the subtree have the same value. For example: Given binary tree, 5 / \ 1 5 / \ \ 5 5 5 return 4. Solution: /** * Definition for a binary tree node. *…

298. Binary Tree Longest Consecutive Sequence 先序遍历,根左右.如果该节点的 value == 父节点value + 1, 则长度+1; 否则重置为1. class Solution { private int res = 0; public int longestConsecutive(TreeNode root) { if(root == null) return 0; dfs(root, root.val, 0); return res; }…