作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 DFS + DFS BFS + DFS 日期 题目地址:https://leetcode.com/problems/path-sum-iii/#/description 题目描述 You are given a binary tree in which each node contains an integer value. Find the num…
437. Path Sum III You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only fro…
You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…
You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…
  相关问题:112 path sum /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: int pathSum(TreeNode* root, int s…
You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…
找遍所有路径,特判以根为起点的串即可. 代码: /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: ; map <int, int> m; int path…
原题: 437. Path Sum III 解题: 思路1就是:以根节点开始遍历找到适合路径,以根节点的左孩子节点开始遍历,然后以根节点的右孩子节点开始遍历,不断循环,也就是以每个节点为起始遍历点 代码如下: class Solution { public: int pathSum(TreeNode* root, int sum) { if(!root) return 0; int count = getPath(root,0,sum) + pathSum(root->left,sum) + p…
[LeetCode]113. Path Sum II 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/path-sum-ii/description/ 题目描述: Given a binary tree and a sum, find all root-to-leaf paths where each…
problem 437. Path Sum III 参考 1. Leetcode_437. Path Sum III; 完…
112. Path Sum 自己的一个错误写法: class Solution { public: bool hasPathSum(TreeNode* root, int sum) { if(root == NULL) return false; ; return hasPathSum(root,sum,value); } bool hasPathSum(TreeNode* root,int sum,int value){ if(root == NULL){ if(value == sum) r…
You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…
作者: 负雪明烛 id: fuxuemingzhu 个人博客:http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 DFS 日期 题目地址:https://leetcode-cn.com/problems/path-sum-iv/ 题目描述 If the depth of a tree is smaller than 5, then this tree can be represented by a list of three-digits integers. Fo…
Path Sum II Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example:Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2], [5,8,4,5] ] SOLUTION…
作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述: 题目大意 解题方法 方法一:DFS 方法二:回溯法 日期 题目地址:https://leetcode.com/problems/combination-sum-iii/description/ 题目描述: Find all possible combinations of k numbers that add up to a number n, given that…
https://www.geeksforgeeks.org/number-subarrays-sum-exactly-equal-k/ 讲解的详细 看这道题是为了解决https://leetcode.com/problems/path-sum-iii/ import java.util.HashMap; import java.util.Map; public class test { static int findSubarraySum(int arr[],int sum){ Map<Inte…
/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: int pathSum(TreeNode* root, int sum) { if (root == NU…
You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…
给定一个二叉树,二叉树的每个节点含有一个整数.找出路径和等于给定数的路径总数.路径不需要从根节点开始,也不需要在叶节点结束,当路径方向必须是向下的(只从父节点到子节点).二叉树不超过1000个节点,节点的整数值的范围是[-1000000,1000000].示例:root = [10,5,-3,3,2,null,11,3,-2,null,1], sum = 8      10     /  \    5   -3   / \    \  3   2   11 / \   \3  -2   1返回…
You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…
作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/unique-paths/description/ 题目描述: A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move either…
Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example:Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1 return true…
Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example:Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2], [5,8,4,5] ] 112. Path Sum 的拓展,上一…
If the depth of a tree is smaller than 5, then this tree can be represented by a list of three-digits integers. For each integer in this list: The hundreds digit represents the depth D of this node, 1 <= D <= 4. The tens digit represents the positio…
首先要说明二叉树的问题就是用递归来做,基本没有其他方法,因为这数据结构基本只能用递归遍历,不要把事情想复杂了. #112 Path Sum 原题链接:https://leetcode.com/problems/path-sum/ . 判断从树的根节点到叶子节点的路径中,是否有一条所有节点上的值之和和特定的数字,即sum. 从根节点到叶子节点,线路的起点的是固定的,只需要不断递归下去,判断在叶子节点处是否满足根节点加到该节点的值之和为sum. 这个限制条件把这个问题简化了很多很多. /** * D…
437. Path Sum III Easy You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling onl…
[LeetCode]556. Next Greater Element III 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/next-greater-element-iii/description/ 题目描述: Given a positive 32-bit integer n, you need…
[LeetCode]306. Additive Number 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/additive-number/description/ 题目描述: Additive number is a string whose digits can form additive se…
[LeetCode]848. Shifting Letters 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/shifting-letters/description/ 题目描述: We have a string S of lowercase letters, and an integer arr…
[LeetCode]554. Brick Wall 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/brick-wall/description/ 题目描述: There is a brick wall in front of you. The wall is rectangular and has…