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leetcode - Path Sum

2013-11-02 21:14  张汉生  阅读(163)  评论(0)    收藏  举报

 

 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     bool hasPathSum(TreeNode *root, int sum) {
13         // IMPORTANT: Please reset any member data you declared, as
14         // the same Solution instance will be reused for each test case.
15         if (root == NULL)
16             return false;
17         if (root->left == NULL && root->right ==NULL && root->val == sum)
18             return true;
19         return hasPathSum(root->left,sum-root->val) || hasPathSum(root->right,sum-root->val);
20     }
21 };