Cinte's Leetcode Record
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112. 路径总和

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Symbols count in article: 745 Reading time ≈ 1 mins.

112. 路径总和

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/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    bool hasPathSum(TreeNode* root, int targetSum) {
        return helper(root, 0, targetSum);
    }
private:
    bool helper(TreeNode* node, int cur, int targetSum)
    {
        if(!node)
            return false;
        cur += node->val;
        if(!node->left && !node->right && cur == targetSum)
            return true;
        return helper(node->left, cur, targetSum) || helper(node->right, cur, targetSum);
    }
};