Added tasks 102-238

Author: javadev

LeetCodeNet/G0001_0100/S0002_add_two_numbers/readme.md

@@ -42,6 +42,16 @@ You may assume the two numbers do not contain any leading zero, except the numbe
 ```csharp
 using LeetCodeNet.Com_github_leetcode;
 
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     int val;
+ *     ListNode next;
+ *     ListNode() {}
+ *     ListNode(int val) { this.val = val; }
+ *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+ * }
+ */
 public class Solution {
     public ListNode AddTwoNumbers(ListNode l1, ListNode l2) {
         ListNode dummyHead = new ListNode(0);

LeetCodeNet/G0001_0100/S0011_container_with_most_water/readme.md

@@ -51,7 +51,6 @@ public class Solution {
         int maxArea = -1;
         int left = 0;
         int right = height.Length - 1;
-
         while (left < right) {
             if (height[left] < height[right]) {
                 maxArea = Math.Max(maxArea, height[left] * (right - left));
@@ -61,7 +60,6 @@ public class Solution {
                 right--;
             }
         }
-
         return maxArea;
     }
 }

LeetCodeNet/G0001_0100/S0019_remove_nth_node_from_end_of_list/readme.md

@@ -41,6 +41,17 @@ Given the `head` of a linked list, remove the `nth` node from the end of the lis
 ```csharp
 using LeetCodeNet.Com_github_leetcode;
 
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public int val;
+ *     public ListNode next;
+ *     public ListNode(int val=0, ListNode next=null) {
+ *         this.val = val;
+ *         this.next = next;
+ *     }
+ * }
+ */
 public class Solution {
     private int n;
 

LeetCodeNet/G0001_0100/S0021_merge_two_sorted_lists/readme.md

@@ -38,6 +38,17 @@ Merge two sorted linked lists and return it as a **sorted** list. The list shoul
 ```csharp
 using LeetCodeNet.Com_github_leetcode;
 
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public int val;
+ *     public ListNode next;
+ *     public ListNode(int val=0, ListNode next=null) {
+ *         this.val = val;
+ *         this.next = next;
+ *     }
+ * }
+ */
 public class Solution {
     public ListNode MergeTwoLists(ListNode l1, ListNode l2) {
         ListNode list = new ListNode(-1);

LeetCodeNet/G0001_0100/S0023_merge_k_sorted_lists/readme.md

@@ -43,6 +43,17 @@ _Merge all the linked-lists into one sorted linked-list and return it._
 ```csharp
 using LeetCodeNet.Com_github_leetcode;
 
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public int val;
+ *     public ListNode next;
+ *     public ListNode(int val=0, ListNode next=null) {
+ *         this.val = val;
+ *         this.next = next;
+ *     }
+ * }
+ */
 public class Solution {
     public ListNode MergeKLists(ListNode[] lists) {
         if (lists.Length == 0) {

LeetCodeNet/G0001_0100/S0024_swap_nodes_in_pairs/readme.md

@@ -37,6 +37,17 @@ Given a linked list, swap every two adjacent nodes and return its head. You must
 ```csharp
 using LeetCodeNet.Com_github_leetcode;
 
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public int val;
+ *     public ListNode next;
+ *     public ListNode(int val=0, ListNode next=null) {
+ *         this.val = val;
+ *         this.next = next;
+ *     }
+ * }
+ */
 public class Solution {
     public ListNode SwapPairs(ListNode head) {
         if (head == null) {

LeetCodeNet/G0001_0100/S0025_reverse_nodes_in_k_group/readme.md

@@ -53,6 +53,17 @@ You may not alter the values in the list's nodes, only nodes themselves may be c
 ```csharp
 using LeetCodeNet.Com_github_leetcode;
 
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     public int val;
+ *     public ListNode next;
+ *     public ListNode(int val=0, ListNode next=null) {
+ *         this.val = val;
+ *         this.next = next;
+ *     }
+ * }
+ */
 public class Solution {
     public ListNode ReverseKGroup(ListNode head, int k) {
         if (head == null || head.next == null || k == 1) {

LeetCodeNet/G0101_0200/S0102_binary_tree_level_order_traversal/readme.md

@@ -0,0 +1,84 @@
+[![](https://img.shields.io/github/stars/LeetCode-in-Net/LeetCode-in-Net?label=Stars&style=flat-square)](https://github.com/LeetCode-in-Net/LeetCode-in-Net)
+[![](https://img.shields.io/github/forks/LeetCode-in-Net/LeetCode-in-Net?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/LeetCode-in-Net/LeetCode-in-Net/fork)
+
+## 102\. Binary Tree Level Order Traversal
+
+Medium
+
+Given the `root` of a binary tree, return _the level order traversal of its nodes' values_. (i.e., from left to right, level by level).
+
+**Example 1:**
+
+![](https://assets.leetcode.com/uploads/2021/02/19/tree1.jpg)
+
+**Input:** root = [3,9,20,null,null,15,7]
+
+**Output:** [[3],[9,20],[15,7]] 
+
+**Example 2:**
+
+**Input:** root = [1]
+
+**Output:** [[1]] 
+
+**Example 3:**
+
+**Input:** root = []
+
+**Output:** [] 
+
+**Constraints:**
+
+*   The number of nodes in the tree is in the range `[0, 2000]`.
+*   `-1000 <= Node.val <= 1000`
+
+## Solution
+
+```csharp
+using LeetCodeNet.Com_github_leetcode;
+
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     public int val;
+ *     public TreeNode left;
+ *     public TreeNode right;
+ *     public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {
+ *         this.val = val;
+ *         this.left = left;
+ *         this.right = right;
+ *     }
+ * }
+ */
+public class Solution {
+    public IList<IList<int>> LevelOrder(TreeNode root) {
+        IList<IList<int>> result = new List<IList<int>>();
+        if (root == null) {
+            return result;
+        }
+        Queue<TreeNode> queue = new Queue<TreeNode>();
+        queue.Enqueue(root);
+        queue.Enqueue(null);
+        List<int> level = new List<int>();
+        while (queue.Count > 0) {
+            root = queue.Dequeue();
+            while (queue.Count > 0 && root != null) {
+                level.Add((int)root.val);
+                if (root.left != null) {
+                    queue.Enqueue(root.left);
+                }
+                if (root.right != null) {
+                    queue.Enqueue(root.right);
+                }
+                root = queue.Dequeue();
+            }
+            result.Add(level);
+            level = new List<int>();
+            if (queue.Count > 0) {
+                queue.Enqueue(null);
+            }
+        }
+        return result;
+    }
+}
+```

LeetCodeNet/G0101_0200/S0104_maximum_depth_of_binary_tree/readme.md

@@ -0,0 +1,75 @@
+[![](https://img.shields.io/github/stars/LeetCode-in-Net/LeetCode-in-Net?label=Stars&style=flat-square)](https://github.com/LeetCode-in-Net/LeetCode-in-Net)
+[![](https://img.shields.io/github/forks/LeetCode-in-Net/LeetCode-in-Net?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/LeetCode-in-Net/LeetCode-in-Net/fork)
+
+## 104\. Maximum Depth of Binary Tree
+
+Easy
+
+Given the `root` of a binary tree, return _its maximum depth_.
+
+A binary tree's **maximum depth** is the number of nodes along the longest path from the root node down to the farthest leaf node.
+
+**Example 1:**
+
+![](https://assets.leetcode.com/uploads/2020/11/26/tmp-tree.jpg)
+
+**Input:** root = [3,9,20,null,null,15,7]
+
+**Output:** 3 
+
+**Example 2:**
+
+**Input:** root = [1,null,2]
+
+**Output:** 2 
+
+**Example 3:**
+
+**Input:** root = []
+
+**Output:** 0 
+
+**Example 4:**
+
+**Input:** root = [0]
+
+**Output:** 1 
+
+**Constraints:**
+
+*   The number of nodes in the tree is in the range <code>[0, 10<sup>4</sup>]</code>.
+*   `-100 <= Node.val <= 100`
+
+## Solution
+
+```csharp
+using LeetCodeNet.Com_github_leetcode;
+
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     public int val;
+ *     public TreeNode left;
+ *     public TreeNode right;
+ *     public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {
+ *         this.val = val;
+ *         this.left = left;
+ *         this.right = right;
+ *     }
+ * }
+ */
+public class Solution {
+    public int MaxDepth(TreeNode root) {
+        return FindDepth(root, 0);
+    }
+
+    private int FindDepth(TreeNode node, int currentDepth) {
+        if (node == null) {
+            return 0;
+        }
+        currentDepth++;
+        return 1
+                + Math.Max(FindDepth(node.left, currentDepth), FindDepth(node.right, currentDepth));
+    }
+}
+```

LeetCodeNet/G0101_0200/S0105_construct_binary_tree_from_preorder_and_inorder_traversal/readme.md

@@ -0,0 +1,80 @@
+[![](https://img.shields.io/github/stars/LeetCode-in-Net/LeetCode-in-Net?label=Stars&style=flat-square)](https://github.com/LeetCode-in-Net/LeetCode-in-Net)
+[![](https://img.shields.io/github/forks/LeetCode-in-Net/LeetCode-in-Net?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/LeetCode-in-Net/LeetCode-in-Net/fork)
+
+## 105\. Construct Binary Tree from Preorder and Inorder Traversal
+
+Medium
+
+Given two integer arrays `preorder` and `inorder` where `preorder` is the preorder traversal of a binary tree and `inorder` is the inorder traversal of the same tree, construct and return _the binary tree_.
+
+**Example 1:**
+
+![](https://assets.leetcode.com/uploads/2021/02/19/tree.jpg)
+
+**Input:** preorder = [3,9,20,15,7], inorder = [9,3,15,20,7]
+
+**Output:** [3,9,20,null,null,15,7] 
+
+**Example 2:**
+
+**Input:** preorder = [-1], inorder = [-1]
+
+**Output:** [-1] 
+
+**Constraints:**
+
+*   `1 <= preorder.length <= 3000`
+*   `inorder.length == preorder.length`
+*   `-3000 <= preorder[i], inorder[i] <= 3000`
+*   `preorder` and `inorder` consist of **unique** values.
+*   Each value of `inorder` also appears in `preorder`.
+*   `preorder` is **guaranteed** to be the preorder traversal of the tree.
+*   `inorder` is **guaranteed** to be the inorder traversal of the tree.
+
+## Solution
+
+```csharp
+using LeetCodeNet.Com_github_leetcode;
+
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     public int val;
+ *     public TreeNode left;
+ *     public TreeNode right;
+ *     public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {
+ *         this.val = val;
+ *         this.left = left;
+ *         this.right = right;
+ *     }
+ * }
+ */
+public class Solution {
+    private int j;
+    private Dictionary<int, int> map = new Dictionary<int, int>();
+
+    public int Get(int key) {
+        return map[key];
+    }
+
+    private TreeNode Answer(int[] preorder, int[] inorder, int start, int end) {
+        if (start > end || j > preorder.Length) {
+            return null;
+        }
+        int value = preorder[j++];
+        int index = Get(value);
+        TreeNode node = new TreeNode(value);
+        node.left = Answer(preorder, inorder, start, index - 1);
+        node.right = Answer(preorder, inorder, index + 1, end);
+        return node;
+    }
+
+    public TreeNode BuildTree(int[] preorder, int[] inorder) {
+        j = 0;
+        for (int i = 0; i < preorder.Length; i++) {
+            map.Add(inorder[i], i);
+        }
+        return Answer(preorder, inorder, 0, preorder.Length - 1);
+    }
+}
+```