Added tasks 1608-1800

src/main/kotlin/g0001_0100/s0093_restore_ip_addresses/readme.md

@@ -37,7 +37,7 @@ Given a string `s` containing only digits, return _all possible valid IP address
 ## Solution
 
 ```kotlin
-class Solution() {
+class Solution {
     fun restoreIpAddresses(s: String): List<String> {
         val results: MutableList<String> = ArrayList()
         step(s, 0, IntArray(4), 0, results)

src/main/kotlin/g0601_0700/s0638_shopping_offers/readme.md

@@ -51,7 +51,7 @@ You cannot add more items, though only $9 for 2A ,2B and 1C.
 ## Solution
 
 ```kotlin
-class Solution() {
+class Solution {
     fun shoppingOffers(
         price: List<Int>,
         special: List<List<Int>>,

src/main/kotlin/g1001_1100/s1039_minimum_score_triangulation_of_polygon/readme.md

@@ -50,7 +50,7 @@ Return _the smallest possible total score that you can achieve with some triangu
 ## Solution
 
 ```kotlin
-class Solution() {
+class Solution {
     private val dp = Array(101) { IntArray(101) }
     fun minScoreTriangulation(values: IntArray): Int {
         val n = values.size

src/main/kotlin/g1301_1400/s1378_replace_employee_id_with_the_unique_identifier/readme.md

@@ -0,0 +1,92 @@
+[![](https://img.shields.io/github/stars/javadev/LeetCode-in-Kotlin?label=Stars&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin)
+[![](https://img.shields.io/github/forks/javadev/LeetCode-in-Kotlin?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin/fork)
+
+## 1378\. Replace Employee ID With The Unique Identifier
+
+Easy
+
+SQL Schema
+
+Table: `Employees`
+
+    +---------------+---------+
+    | Column Name   | Type    |
+    +---------------+---------+
+    | id            | int     |
+    | name          | varchar |
+    +---------------+---------+
+    id is the primary key for this table.
+    Each row of this table contains the id and the name of an employee in a company. 
+
+Table: `EmployeeUNI`
+
+    +---------------+---------+
+    | Column Name   | Type    |
+    +---------------+---------+
+    | id            | int     |
+    | unique_id     | int     |
+    +---------------+---------+ 
+    (id, unique_id) is the primary key for this table.
+    Each row of this table contains the id and the corresponding unique id of an employee in the company. 
+
+Write an SQL query to show the **unique ID** of each user, If a user does not have a unique ID replace just show `null`.
+
+Return the result table in **any** order.
+
+The query result format is in the following example.
+
+**Example 1:**
+
+**Input:**,
+
+    Employees table:
+    +----+----------+
+    | id | name     |
+    +----+----------+
+    | 1  | Alice    |
+    | 7  | Bob      |
+    | 11 | Meir     |
+    | 90 | Winston  |
+    | 3  | Jonathan |
+    +----+----------+
+
+    EmployeeUNI table:
+    +----+-----------+
+    | id | unique_id |
+    +----+-----------+
+    | 3  | 1         |
+    | 11 | 2         |
+    | 90 | 3         |
+    +----+-----------+
+
+**Output:**
+
+    +-----------+----------+
+    | unique_id | name     |
+    +-----------+----------+
+    | null      | Alice    |
+    | null      | Bob      |
+    | 2         | Meir     |
+    | 3         | Winston  |
+    | 1         | Jonathan |
+    +-----------+----------+
+
+**Explanation:**
+
+Alice and Bob do not have a unique ID, We will show null instead.
+
+The unique ID of Meir is 2.
+
+The unique ID of Winston is 3.
+
+The unique ID of Jonathan is 1.
+
+## Solution
+
+```sql
+# Write your MySQL query statement below
+select u.unique_id, e.name
+from Employees e
+left join EmployeeUNI u
+on e.id = u.id;
+```

src/main/kotlin/g1501_1600/s1517_find_users_with_valid_e_mails/readme.md

@@ -0,0 +1,76 @@
+[![](https://img.shields.io/github/stars/javadev/LeetCode-in-Kotlin?label=Stars&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin)
+[![](https://img.shields.io/github/forks/javadev/LeetCode-in-Kotlin?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin/fork)
+
+## 1517\. Find Users With Valid E-Mails
+
+Easy
+
+SQL Schema
+
+Table: `Users`
+
+    +---------------+---------+
+    | Column Name   | Type    |
+    +---------------+---------+
+    | user_id       | int     |
+    | name          | varchar |
+    | mail          | varchar |
+    +---------------+---------+
+    user_id is the primary key for this table.
+    This table contains information of the users signed up in a website. Some e-mails are invalid. 
+
+Write an SQL query to find the users who have **valid emails**.
+
+A valid e-mail has a prefix name and a domain where:
+
+*   **The prefix name** is a string that may contain letters (upper or lower case), digits, underscore `'_'`, period `'.'`, and/or dash `'-'`. The prefix name **must** start with a letter.
+*   **The domain** is `'@leetcode.com'`.
+
+Return the result table in **any order**.
+
+The query result format is in the following example.
+
+**Example 1:**
+
+**Input:**
+
+    Users table:
+    +---------+-----------+-------------------------+
+    | user_id | name      | mail                    |
+    +---------+-----------+-------------------------+
+    | 1       | Winston   | winston@leetcode.com    |
+    | 2       | Jonathan  | jonathanisgreat         |
+    | 3       | Annabelle | bella-@leetcode.com     |
+    | 4       | Sally     | sally.come@leetcode.com |
+    | 5       | Marwan    | quarz#2020@leetcode.com |
+    | 6       | David     | david69@gmail.com       |
+    | 7       | Shapiro   | .shapo@leetcode.com     |
+    +---------+-----------+-------------------------+
+
+**Output:**
+
+    +---------+-----------+-------------------------+
+    | user_id | name      | mail                    |
+    +---------+-----------+-------------------------+
+    | 1       | Winston   | winston@leetcode.com    |
+    | 3       | Annabelle | bella-@leetcode.com     |
+    | 4       | Sally     | sally.come@leetcode.com |
+    +---------+-----------+-------------------------+
+
+**Explanation:**
+
+The mail of user 2 does not have a domain.
+
+The mail of user 5 has the # sign which is not allowed.
+
+The mail of user 6 does not have the leetcode domain.
+
+The mail of user 7 starts with a period.
+
+## Solution
+
+```sql
+# Write your MySQL query statement below
+select * from Users
+where mail REGEXP '^[a-zA-Z][a-zA-Z0-9_.-]*@leetcode.com' and mail LIKE '%@leetcode.com'
+```

src/main/kotlin/g1601_1700/s1608_special_array_with_x_elements_greater_than_or_equal_x/readme.md

@@ -0,0 +1,72 @@
+[![](https://img.shields.io/github/stars/javadev/LeetCode-in-Kotlin?label=Stars&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin)
+[![](https://img.shields.io/github/forks/javadev/LeetCode-in-Kotlin?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin/fork)
+
+## 1608\. Special Array With X Elements Greater Than or Equal X
+
+Easy
+
+You are given an array `nums` of non-negative integers. `nums` is considered **special** if there exists a number `x` such that there are **exactly** `x` numbers in `nums` that are **greater than or equal to** `x`.
+
+Notice that `x` **does not** have to be an element in `nums`.
+
+Return `x` _if the array is **special**, otherwise, return_ `-1`. It can be proven that if `nums` is special, the value for `x` is **unique**.
+
+**Example 1:**
+
+**Input:** nums = [3,5]
+
+**Output:** 2
+
+**Explanation:** There are 2 values (3 and 5) that are greater than or equal to 2.
+
+**Example 2:**
+
+**Input:** nums = [0,0]
+
+**Output:** -1
+
+**Explanation:** No numbers fit the criteria for x. 
+
+If x = 0, there should be 0 numbers >= x, but there are 2. 
+
+If x = 1, there should be 1 number >= x, but there are 0. 
+
+If x = 2, there should be 2 numbers >= x, but there are 0. 
+
+x cannot be greater since there are only 2 numbers in nums.
+
+**Example 3:**
+
+**Input:** nums = [0,4,3,0,4]
+
+**Output:** 3
+
+**Explanation:** There are 3 values that are greater than or equal to 3.
+
+**Constraints:**
+
+*   `1 <= nums.length <= 100`
+*   `0 <= nums[i] <= 1000`
+
+## Solution
+
+```kotlin
+class Solution {
+    fun specialArray(nums: IntArray): Int {
+        nums.sort()
+        val max = nums[nums.size - 1]
+        for (x in 1..max) {
+            var found = 0
+            var i = nums.size - 1
+            while (i >= 0 && nums[i] >= x) {
+                i--
+                found++
+            }
+            if (found == x) {
+                return x
+            }
+        }
+        return -1
+    }
+}
+```

src/main/kotlin/g1601_1700/s1609_even_odd_tree/readme.md

@@ -0,0 +1,118 @@
+[![](https://img.shields.io/github/stars/javadev/LeetCode-in-Kotlin?label=Stars&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin)
+[![](https://img.shields.io/github/forks/javadev/LeetCode-in-Kotlin?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin/fork)
+
+## 1609\. Even Odd Tree
+
+Medium
+
+A binary tree is named **Even-Odd** if it meets the following conditions:
+
+*   The root of the binary tree is at level index `0`, its children are at level index `1`, their children are at level index `2`, etc.
+*   For every **even-indexed** level, all nodes at the level have **odd** integer values in **strictly increasing** order (from left to right).
+*   For every **odd-indexed** level, all nodes at the level have **even** integer values in **strictly decreasing** order (from left to right).
+
+Given the `root` of a binary tree, _return_ `true` _if the binary tree is **Even-Odd**, otherwise return_ `false`_._
+
+**Example 1:**
+
+![](https://assets.leetcode.com/uploads/2020/09/15/sample_1_1966.png)
+
+**Input:** root = [1,10,4,3,null,7,9,12,8,6,null,null,2]
+
+**Output:** true
+
+**Explanation:** The node values on each level are: 
+
+Level 0: [1] 
+
+Level 1: [10,4] 
+
+Level 2: [3,7,9]
+
+Level 3: [12,8,6,2] 
+
+Since levels 0 and 2 are all odd and increasing and levels 1 and 3 are all even and decreasing, the tree is Even-Odd.
+
+**Example 2:**
+
+![](https://assets.leetcode.com/uploads/2020/09/15/sample_2_1966.png)
+
+**Input:** root = [5,4,2,3,3,7]
+
+**Output:** false
+
+**Explanation:** The node values on each level are:
+
+Level 0: [5]
+
+Level 1: [4,2] 
+
+Level 2: [3,3,7] 
+
+Node values in level 2 must be in strictly increasing order, so the tree is not Even-Odd.
+
+**Example 3:**
+
+![](https://assets.leetcode.com/uploads/2020/09/22/sample_1_333_1966.png)
+
+**Input:** root = [5,9,1,3,5,7]
+
+**Output:** false
+
+**Explanation:** Node values in the level 1 should be even integers.
+
+**Constraints:**
+
+*   The number of nodes in the tree is in the range <code>[1, 10<sup>5</sup>]</code>.
+*   <code>1 <= Node.val <= 10<sup>6</sup></code>
+
+## Solution
+
+```kotlin
+import com_github_leetcode.TreeNode
+
+/*
+ * Example:
+ * var ti = TreeNode(5)
+ * var v = ti.`val`
+ * Definition for a binary tree node.
+ * class TreeNode(var `val`: Int) {
+ *     var left: TreeNode? = null
+ *     var right: TreeNode? = null
+ * }
+ */
+class Solution {
+    private val comp: MutableList<Int> = ArrayList()
+
+    fun isEvenOddTree(root: TreeNode?): Boolean {
+        return find(root, 0)
+    }
+
+    private fun find(root: TreeNode?, height: Int): Boolean {
+        if (root == null) {
+            return true
+        }
+        if (height % 2 == 0 && root.`val` % 2 == 0 || height % 2 == 1 && root.`val` % 2 == 1) {
+            return false
+        }
+        if (comp.size == height) {
+            comp.add(root.`val`)
+        } else {
+            if (height % 2 == 0) {
+                if (comp[height] >= root.`val`) {
+                    return false
+                } else {
+                    comp[height] = root.`val`
+                }
+            } else {
+                if (comp[height] <= root.`val`) {
+                    return false
+                } else {
+                    comp[height] = root.`val`
+                }
+            }
+        }
+        return find(root.left, height + 1) && find(root.right, height + 1)
+    }
+}
+```