leetcode Path Sum

原题链接：https://leetcode.com/problems/path-sum/

/** * 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) {        return dfs(root, 0, sum);    }    bool dfs(TreeNode *x, int cur, int sum) {        if (!x) return false;        if (!x->left && !x->right) {            if (sum == cur + x->val) return true;        }        if (dfs(x->left, cur + x->val, sum)) return true;        if (dfs(x->right, cur + x->val, sum)) return true;        return false;    }};