路径总和II
![](https://img2022.cnblogs.com/blog/1468919/202206/1468919-20220629215220870-987937295.png)
https://leetcode.cn/problems/path-sum-ii/
/** * Definition for a binary tree node. * type TreeNode struct { * Val int * Left *TreeNode * Right *TreeNode * } */ func pathSum(root *TreeNode, targetSum int) [][]int { stack:=make([]int,0) ways=make([][]int,0) dfs(root,0,targetSum,stack) return ways } var ways [][]int func dfs(now *TreeNode,ans,target int,stack []int){ if now==nil{//递归出口,可能有正数,也可能有负数 return } ans=ans+now.Val stack=append(stack,now.Val) if ans==target&&now.Left==nil&&now.Right==nil{//只有到叶子节点,并且和为target才可以 tmp:=make([]int,len(stack)) copy(tmp,stack) ways=append(ways,tmp) } dfs(now.Left,ans,target,stack) dfs(now.Right,ans,target,stack) ans=ans-now.Val stack=stack[:len(stack)-1] }
二叉树的建立:https://www.cnblogs.com/-citywall123/p/16434923.html
等风起的那一天,我已准备好一切