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…

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…

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…

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…

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…

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…

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…