Path Sum I 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. Note: A leaf is a node with no children. Example: Given the below binary tree and sum = 22…

Path Sum 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 re…

LeetCode:Path Sum 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 / \ \…

  I 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…

1.  Path Sum 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…

1. Given an array of integers, return indices of the two numbers such that they add up to a specific target. 问题: 1.数组是否有序 2. 数组排序 // sorting array Arrays.sort(iArr) 方法1:O(n^2) public class Solution { public int[] twoSum(int[] nums, int target) { int[…

Combination Sum Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. The same repeated number may be chosen from C unlimited number of times. Note: All numbers (includi…

Two Sum I Given an array of integers, find two numbers such that they add up to a specific target number. The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. You may…

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…

II 简单dfs vector<vector<int>> combinationSum2(vector<int>& candidates, int target) { vector<vector<int>> ans; vector<int> cur; sort(candidates.begin(), candidates.end()); // 排序后去重 dfs(,target,candidates,cur,ans); ret…

Title: https://leetcode.com/problems/combination-sum/ Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. The same repeated number may be chosen from C unlimited numbe…

问题 给出一棵二叉树及一个和值,检查该树是否存在一条根到叶子的路径,该路径经过的所有节点值的和等于给出的和值. 例如, 给出以下二叉树及和值22: 5         / \       4  8      /   / \    11 13 4    / \        \  7   2        1 函数返回true,因为存在一条根到叶子的路径5->4->11->2,其路径和为22. 初始思路 鉴于题目要求找到一条路径和符合要求即可,选择层次遍历二叉树是一种比较合适的选择-保证了…

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…

题目链接:Path Sum II | LeetCode OJ 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],…

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…

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] ] 这道二叉树路径之和在之前的基础上又需要找…

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]] 分析: dfs求解即可…

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] ] 这个问题需要返…

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] ]     采用深度…

Path Sum OJ: https://oj.leetcode.com/problems/path-sum/ 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…

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…

Problem 1 [Balanced Binary Tree] Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1. Pr…

Path Sum Total Accepted: 81706 Total Submissions: 269391 Difficulty: Easy 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…

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…

Path Sum 题目链接 题目要求: 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 /…

之所以将这三道题放在一起,是因为这三道题非常类似. 1. Minimum Path Sum 题目链接 题目要求: Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path. Note: You can only move either down or righ…

problem 437. Path Sum III 参考 1. Leetcode_437. Path Sum III; 完…

LeetCode 二叉树路径问题 Path SUM(①②③)总结 Path Sum II leetcode java 描述 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 / \ / \…

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…

目录 题目链接 注意点 解法 小结 题目链接 Path Sum II - LeetCode 注意点 不要访问空结点 解法 解法一:递归,DFS.每当DFS搜索到新节点时,都要保存该节点.而且每当找出一条路径之后,都将这个保存为一维vector的路径保存到最终结果二维vector中.并且,每当DFS搜索到子节点,发现不是路径和时,返回上一个结点时,需要把该节点从一维vector中移除. /** * Definition for a binary tree node. * struct TreeNo…