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.me/ 文章目录 题目描述 题目大意 解题方法 BFS DFS 日期 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 path's sum equals the given…
题目: Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. Note: A leaf is a node with no children. Example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 Return: [ […
https://leetcode.com/problems/path-sum-iii/ 理解比较困难,可以先看https://www.cnblogs.com/albert67/p/10416402.html /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } *…
找出所有可能的 k 个数,使其相加之和为 n,只允许使用数字1-9,并且每一种组合中的数字是唯一的.示例 1:输入: k = 3, n = 7输出:[[1,2,4]]示例 2:输入: k = 3, n = 9输出:[[1,2,6], [1,3,5], [2,3,4]]详见:https://leetcode.com/problems/combination-sum-iii/description/ Java实现: class Solution { public List<List<Integer…