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.
Code:
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/** * Definition for binary tree * 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) return
false; if(!root->left&&!root->right&&root->val==sum) return
true; else return
hasPathSum(root->left,sum-root->val)||hasPathSum(root->right,sum-root->val); }}; |
原文：http://www.cnblogs.com/winscoder/p/3535387.html