leetcode-華為專題-129. 求根節點到葉節點數字之和
阿新 • • 發佈:2021-08-15
/** * 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: vector<int> res; int sumNumbers(TreeNode* root) { if(root==NULL) return 0; dfs(root, 0); int tmp = 0; for(int i = 0; i < res.size(); i++){ // cout<<i<<": "<<res[i]<<endl; tmp = tmp + res[i]; }return tmp; } void dfs(TreeNode* root,int sum){ if(root==NULL) return; if(root->left==NULL&&root->right==NULL){ sum = sum*10 + root->val; res.push_back(sum); return; } sum = sum*10 + root->val; dfs(root->left, sum); dfs(root->right, sum); } };