Chapter 06 section 02, 03 comments updated.

Author: liuyubobobo

06-Stack-and-Queue/Course Code (C++)/02-Recursion-and-Stack/main.cpp

@@ -6,6 +6,8 @@ using namespace std;
 /// 144. Binary Tree Preorder Traversal
 /// https://leetcode.com/problems/binary-tree-preorder-traversal/description/
 /// 二叉树的前序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 
 /// Definition for a binary tree node.
 struct TreeNode {

06-Stack-and-Queue/Course Code (C++)/02-Recursion-and-Stack/main2.cpp

@@ -6,6 +6,8 @@ using namespace std;
 /// 94. Binary Tree Inorder Traversal
 /// https://leetcode.com/problems/binary-tree-inorder-traversal/solution/
 /// 二叉树的中序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 
 /// Definition for a binary tree node.
 struct TreeNode {

06-Stack-and-Queue/Course Code (C++)/02-Recursion-and-Stack/main3.cpp

@@ -6,6 +6,8 @@ using namespace std;
 /// 145. Binary Tree Postorder Traversal
 /// https://leetcode.com/problems/binary-tree-postorder-traversal/description/
 /// 二叉树的后序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 
 /// Definition for a binary tree node.
 struct TreeNode {

06-Stack-and-Queue/Course Code (C++)/03-Non-Recursive-Implementation-of-a-Recursive-Algorithm/main.cpp

@@ -8,6 +8,8 @@ using namespace std;
 /// 144. Binary Tree Preorder Traversal
 /// https://leetcode.com/problems/binary-tree-preorder-traversal/description/
 /// 非递归的二叉树的前序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 
 /// Definition for a binary tree node.
 struct TreeNode {

06-Stack-and-Queue/Course Code (C++)/03-Non-Recursive-Implementation-of-a-Recursive-Algorithm/main2.cpp

@@ -6,6 +6,8 @@ using namespace std;
 /// 94. Binary Tree Inorder Traversal
 /// https://leetcode.com/problems/binary-tree-inorder-traversal/solution/
 /// 非递归的二叉树的中序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 
 /// Definition for a binary tree node.
 struct TreeNode {

06-Stack-and-Queue/Course Code (C++)/03-Non-Recursive-Implementation-of-a-Recursive-Algorithm/main3.cpp

@@ -7,6 +7,8 @@ using namespace std;
 /// 145. Binary Tree Postorder Traversal
 /// https://leetcode.com/problems/binary-tree-postorder-traversal/description/
 /// 非递归的二叉树的后序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 
 /// Definition for a binary tree node.
 struct TreeNode {

06-Stack-and-Queue/Course Code (C++)/04-Binary-Tree-Level-Order-Traversal/main.cpp

@@ -5,6 +5,9 @@
 
 using namespace std;
 
+/// 102. Binary Tree Level Order Traversal
+/// https://leetcode.com/problems/binary-tree-level-order-traversal/description/
+
 /// Definition for a binary tree node.
 struct TreeNode {
     int val;
@@ -22,23 +25,23 @@ class Solution {
             return res;
 
         queue<pair<TreeNode*,int>> q;
-        q.push( make_pair( root , 0 ) );
+        q.push(make_pair(root, 0 ));
 
-        while( !q.empty() ){
+        while(!q.empty()){
 
             TreeNode* node = q.front().first;
             int level = q.front().second;
             q.pop();
 
-            if( level == res.size() )
-                res.push_back( vector<int>() );
+            if(level == res.size())
+                res.push_back(vector<int>());
             assert( level < res.size() );
 
-            res[level].push_back( node->val );
-            if( node->left )
-                q.push( make_pair(node->left, level + 1 ) );
-            if( node->right )
-                q.push( make_pair(node->right, level + 1 ) );
+            res[level].push_back(node->val);
+            if(node->left)
+                q.push(make_pair(node->left, level + 1 ));
+            if(node->right)
+                q.push(make_pair(node->right, level + 1 ));
         }
 
         return res;

06-Stack-and-Queue/Course Code (Java)/02-Recursion-and-Stack/src/Solution094.java

@@ -4,6 +4,8 @@
 /// 94. Binary Tree Inorder Traversal
 /// https://leetcode.com/problems/binary-tree-inorder-traversal/solution/
 /// 二叉树的中序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 public class Solution094 {
 
     // Definition for a binary tree node.

06-Stack-and-Queue/Course Code (Java)/02-Recursion-and-Stack/src/Solution144.java

@@ -4,6 +4,8 @@
 /// 144. Binary Tree Preorder Traversal
 /// https://leetcode.com/problems/binary-tree-preorder-traversal/description/
 /// 二叉树的前序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 public class Solution144 {
 
     // Definition for a binary tree node.

06-Stack-and-Queue/Course Code (Java)/02-Recursion-and-Stack/src/Solution145.java

@@ -4,6 +4,8 @@
 /// 145. Binary Tree Postorder Traversal
 /// https://leetcode.com/problems/binary-tree-postorder-traversal/description/
 /// 二叉树的后序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 public class Solution145 {
 
     // Definition for a binary tree node.

06-Stack-and-Queue/Course Code (Java)/03-Non-Recursive-Implementation-of-a-Recursive-Algorithm/src/Solution094.java

@@ -5,6 +5,8 @@
 /// 94. Binary Tree Inorder Traversal
 /// https://leetcode.com/problems/binary-tree-inorder-traversal/solution/
 /// 非递归二叉树的中序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 public class Solution094 {
 
     // Definition for a binary tree node.

06-Stack-and-Queue/Course Code (Java)/03-Non-Recursive-Implementation-of-a-Recursive-Algorithm/src/Solution144.java

@@ -5,6 +5,8 @@
 /// 144. Binary Tree Preorder Traversal
 /// https://leetcode.com/problems/binary-tree-preorder-traversal/description/
 /// 非递归二叉树的前序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 public class Solution144 {
 
     // Definition for a binary tree node.

06-Stack-and-Queue/Course Code (Java)/03-Non-Recursive-Implementation-of-a-Recursive-Algorithm/src/Solution145.java

@@ -5,6 +5,8 @@
 /// 145. Binary Tree Postorder Traversal
 /// https://leetcode.com/problems/binary-tree-postorder-traversal/description/
 /// 非递归的二叉树的后序遍历
+/// 时间复杂度: O(n), n为树的节点个数
+/// 空间复杂度: O(h), h为树的高度
 public class Solution145 {
 
     // Definition for a binary tree node.