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 hasPathSum(TreeNode* root, int sum) {
return sumCount(root, sum, 0);
}

bool sumCount(TreeNode* node, int sum, int curSum){
if(node == NULL)
return false;

if(node->left == NULL && node->right == NULL){
return (curSum + node->val) == sum;
}else{
return sumCount(node->left, sum, curSum + node->val) || sumCount(node->right, sum, curSum + node->val);
}
}
};