题目
2. 算法
* dfs
3. 代码
class Solution {
public:
bool hasPathSum(TreeNode *root, int sum) {
if (root == NULL) return false;
if (root->left == NULL && root->right == NULL && root->val == sum ) return true;
return hasPathSum(root->left, sum - root->val) || hasPathSum(root->right, sum - root->val);
}
};