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59 lines
1.2 KiB
Markdown
Executable File
59 lines
1.2 KiB
Markdown
Executable File
# [112. Path Sum](https://leetcode.com/problems/path-sum/)
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## 题目
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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.
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**Note**: A leaf is a node with no children.
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**Example**:
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Given the below binary tree and `sum = 22`,
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5
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/ \
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4 8
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/ / \
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11 13 4
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/ \ \
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7 2 1
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return true, as there exist a root-to-leaf path `5->4->11->2` which sum is 22.
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## 题目大意
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给定一个二叉树和一个目标和，判断该树中是否存在根节点到叶子节点的路径，这条路径上所有节点值相加等于目标和。说明: 叶子节点是指没有子节点的节点。
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## 解题思路
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- 递归求解即可
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## 代码
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```go
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package leetcode
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/**
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* Definition for a binary tree node.
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* type TreeNode struct {
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* Val int
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* Left *TreeNode
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* Right *TreeNode
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* }
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*/
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func hasPathSum(root *TreeNode, sum int) bool {
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if root == nil {
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return false
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}
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if root.Left == nil && root.Right == nil {
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return sum == root.Val
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}
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return hasPathSum(root.Left, sum-root.Val) || hasPathSum(root.Right, sum-root.Val)
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}
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``` |