leetcode-back-257. 二叉樹的所有路徑
阿新 • • 發佈：2021-08-13
/** * 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<string> res; vector<string> binaryTreePaths(TreeNode* root) { if(root==NULL) return res; string temp =""; back(root,temp); return res; } void back(TreeNode* root, string &temp){ if(root==NULL) return; string temp1 = to_string(root->val); string val = temp1.append("->"); temp.append(val); if(root->left==NULL&&root->right==NULL){ temp = temp.substr(0,temp.size()-2); res.push_back(temp); temp= temp.substr(0,temp.size()-to_string(root->val).size()); // 回溯 return; } back(root->left, temp); back(root->right, temp); temp = temp.substr(0,temp.size()-val.size()); // 回溯 } };