/*** 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:void traversal(TreeNode *cur,vector<int>&vec){if (cur == nullptr) return;vec.push_back(cur->val);traversal(cur->left,vec);traversal(cur->right,vec);}vector<int> preorderTraversal(TreeNode* root) {vector<int>result;traversal(root,result);return result;}
};

中序遍历

/*** 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:void traversal(TreeNode *cur,vector<int>&vec){if (cur == nullptr) return;traversal(cur->left,vec);vec.push_back(cur->val);traversal(cur->right,vec);}vector<int> inorderTraversal(TreeNode* root) {vector<int>result;traversal(root,result);return result;}
};

后序遍历

/*** 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:void traversal(TreeNode *cur,vector<int>&vec){if (cur == nullptr) return;traversal(cur->left,vec);traversal(cur->right,vec);vec.push_back(cur->val);}vector<int> postorderTraversal(TreeNode* root) {vector<int>result;traversal(root,result);return result;}
};