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.

/**
* 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) {
if(root == NULL)
return false;
if(root->left == NULL && root->right == NULL && sum == root->val)
return true;
if(hasPathSum(root->left, sum - root->val) || hasPathSum(root->right, sum - root->val))
return true;
else
return false;
}
};

bool hasPathSum(TreeNode* root, int sum){
if(root == NULL)
return false;
queue<TreeNode*> q;
q.push(root);
TreeNode* temp;
while(!q.empty()){
int size = q.size();
while(size--){
temp = q.front();
q.pop();
if(temp->left != NULL){
q.push(temp->left);
temp->left->val += temp->val;
}
if(temp->right != NULL){
q.push(temp->right);
temp->right->val += temp->val;
}
if(temp->left == NULL && temp->right == NULL && (temp->val == sum)){
return true;
}
}
}
return false;
}