Leetcoede 112 Path Sum 二叉树

 1 /**
 2  * Definition for binary tree
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12 
13 bool hasPathSum(TreeNode *root, int sum) {
14     if (!root)
15     {
16         return false;
17     }
18     if (!root->left && !root->right)
19     {
20         return sum == root->val;
21     }
22     return hasPathSum(root->left,sum - root->val)||hasPathSum(root->right,sum - root->val);
23 }