代码随想录刷题第11天 | 二叉树前中后序遍历
cpp
复制代码
/**
* 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
cpp
复制代码
/**
* 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
cpp
复制代码
/**
* 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;
}
};