Leetcode66: 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.

/**
* Definition for a binary tree node.
* struct TreeNode {
*     int val;
*     TreeNode *left;
*     TreeNode *right;
*     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
bool dfs(TreeNode* Node, int sum, int cursum)
{
if(Node == NULL)
return false;
if(!Node->left && !Node->right)
return Node->val+cursum == sum;
return dfs(Node->left, sum, cursum+Node->val) || dfs(Node->right, sum, cursum+Node->val);
}
bool hasPathSum(TreeNode* root, int sum) {
return dfs(root, sum, 0);
}
};