Leetcode# 112 Path Sum
2015-08-09 18:56
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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
return true, as there exist a root-to-leaf path
Difficulty:Easy
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->2which sum is 22.
Difficulty:Easy
/** * 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(sum-root->val==0&&root->left==NULL&&root->right==NULL) return true; if(hasPathSum(root->left,sum-root->val)||hasPathSum(root->right,sum-root->val)) return true; return false; } };
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