# Leetcode 112: 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
```

return true, as there exist a root-to-leaf path `5->4->11->2` which sum is 22.

``` 1 /**
2  * Definition for a binary tree node.
3  * public class TreeNode {
4  *     public int val;
5  *     public TreeNode left;
6  *     public TreeNode right;
7  *     public TreeNode(int x) { val = x; }
8  * }
9  */
10 public class Solution {
11     public bool HasPathSum(TreeNode root, int sum) {
12         return DFS(root, 0, sum);
13     }
14
15     private bool DFS(TreeNode node, int cur, int sum)
16     {
17         if (node == null) return false;
18
19         if (node.left == null && node.right == null)
20         {
21             return cur + node.val == sum;
22         }
23
24         return DFS(node.left, cur + node.val, sum) || DFS(node.right, cur + node.val, sum);
25     }
26 }```

Leetcode 112: Path Sum

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