Added tasks 3216-3220

src/main/kotlin/g3201_3300/s3216_lexicographically_smallest_string_after_a_swap/Solution.kt

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+package g3201_3300.s3216_lexicographically_smallest_string_after_a_swap
+
+// #Easy #String #Greedy #2024_07_19_Time_157_ms_(95.16%)_Space_35.4_MB_(88.71%)
+
+class Solution {
+    fun getSmallestString(s: String): String {
+        val arr = s.toCharArray()
+        for (i in 1 until arr.size) {
+            if (arr[i - 1].code % 2 == arr[i].code % 2 && arr[i - 1] > arr[i]) {
+                val temp = arr[i]
+                arr[i] = arr[i - 1]
+                arr[i - 1] = temp
+                break
+            }
+        }
+        return String(arr)
+    }
+}

src/main/kotlin/g3201_3300/s3216_lexicographically_smallest_string_after_a_swap/readme.md

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+3216\. Lexicographically Smallest String After a Swap
+
+Easy
+
+Given a string `s` containing only digits, return the lexicographically smallest string that can be obtained after swapping **adjacent** digits in `s` with the same **parity** at most **once**.
+
+Digits have the same parity if both are odd or both are even. For example, 5 and 9, as well as 2 and 4, have the same parity, while 6 and 9 do not.
+
+**Example 1:**
+
+**Input:** s = "45320"
+
+**Output:** "43520"
+
+**Explanation:**
+
+`s[1] == '5'` and `s[2] == '3'` both have the same parity, and swapping them results in the lexicographically smallest string.
+
+**Example 2:**
+
+**Input:** s = "001"
+
+**Output:** "001"
+
+**Explanation:**
+
+There is no need to perform a swap because `s` is already the lexicographically smallest.
+
+**Constraints:**
+
+*   `2 <= s.length <= 100`
+*   `s` consists only of digits.

src/main/kotlin/g3201_3300/s3217_delete_nodes_from_linked_list_present_in_array/Solution.kt

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+package g3201_3300.s3217_delete_nodes_from_linked_list_present_in_array
+
+// #Medium #Array #Hash_Table #Linked_List #2024_07_19_Time_872_ms_(98.31%)_Space_71.9_MB_(93.22%)
+
+import com_github_leetcode.ListNode
+import kotlin.math.max
+
+/*
+ * Example:
+ * var li = ListNode(5)
+ * var v = li.`val`
+ * Definition for singly-linked list.
+ * class ListNode(var `val`: Int) {
+ *     var next: ListNode? = null
+ * }
+ */
+class Solution {
+    fun modifiedList(nums: IntArray, head: ListNode?): ListNode? {
+        var maxv = 0
+        for (v in nums) {
+            maxv = max(maxv, v)
+        }
+        val rem = BooleanArray(maxv + 1)
+        for (v in nums) {
+            rem[v] = true
+        }
+        val h = ListNode(0)
+        var t = h
+        var p = head
+        while (p != null) {
+            if (p.`val` > maxv || !rem[p.`val`]) {
+                t.next = p
+                t = p
+            }
+            p = p.next
+        }
+        t.next = null
+        return h.next
+    }
+}

src/main/kotlin/g3201_3300/s3217_delete_nodes_from_linked_list_present_in_array/readme.md

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+3217\. Delete Nodes From Linked List Present in Array
+
+Medium
+
+You are given an array of integers `nums` and the `head` of a linked list. Return the `head` of the modified linked list after **removing** all nodes from the linked list that have a value that exists in `nums`.
+
+**Example 1:**
+
+**Input:** nums = [1,2,3], head = [1,2,3,4,5]
+
+**Output:** [4,5]
+
+**Explanation:**
+
+**![](https://assets.leetcode.com/uploads/2024/06/11/linkedlistexample0.png)**
+
+Remove the nodes with values 1, 2, and 3.
+
+**Example 2:**
+
+**Input:** nums = [1], head = [1,2,1,2,1,2]
+
+**Output:** [2,2,2]
+
+**Explanation:**
+
+![](https://assets.leetcode.com/uploads/2024/06/11/linkedlistexample1.png)
+
+Remove the nodes with value 1.
+
+**Example 3:**
+
+**Input:** nums = [5], head = [1,2,3,4]
+
+**Output:** [1,2,3,4]
+
+**Explanation:**
+
+**![](https://assets.leetcode.com/uploads/2024/06/11/linkedlistexample2.png)**
+
+No node has value 5.
+
+**Constraints:**
+
+*   <code>1 <= nums.length <= 10<sup>5</sup></code>
+*   <code>1 <= nums[i] <= 10<sup>5</sup></code>
+*   All elements in `nums` are unique.
+*   The number of nodes in the given list is in the range <code>[1, 10<sup>5</sup>]</code>.
+*   <code>1 <= Node.val <= 10<sup>5</sup></code>
+*   The input is generated such that there is at least one node in the linked list that has a value not present in `nums`.

src/main/kotlin/g3201_3300/s3218_minimum_cost_for_cutting_cake_i/Solution.kt

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+package g3201_3300.s3218_minimum_cost_for_cutting_cake_i
+
+// #Medium #Array #Dynamic_Programming #Sorting #Greedy
+// #2024_07_19_Time_175_ms_(78.05%)_Space_35.1_MB_(100.00%)
+
+import kotlin.math.min
+
+class Solution {
+    fun minimumCost(m: Int, n: Int, horizontalCut: IntArray, verticalCut: IntArray): Int {
+        var sum = 0
+        for (hc in horizontalCut) {
+            sum += hc
+        }
+        for (vc in verticalCut) {
+            sum += vc
+        }
+        for (hc in horizontalCut) {
+            for (vc in verticalCut) {
+                sum += min(hc, vc)
+            }
+        }
+        return sum
+    }
+}

src/main/kotlin/g3201_3300/s3218_minimum_cost_for_cutting_cake_i/readme.md

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+3218\. Minimum Cost for Cutting Cake I
+
+Medium
+
+There is an `m x n` cake that needs to be cut into `1 x 1` pieces.
+
+You are given integers `m`, `n`, and two arrays:
+
+*   `horizontalCut` of size `m - 1`, where `horizontalCut[i]` represents the cost to cut along the horizontal line `i`.
+*   `verticalCut` of size `n - 1`, where `verticalCut[j]` represents the cost to cut along the vertical line `j`.
+
+In one operation, you can choose any piece of cake that is not yet a `1 x 1` square and perform one of the following cuts:
+
+1.  Cut along a horizontal line `i` at a cost of `horizontalCut[i]`.
+2.  Cut along a vertical line `j` at a cost of `verticalCut[j]`.
+
+After the cut, the piece of cake is divided into two distinct pieces.
+
+The cost of a cut depends only on the initial cost of the line and does not change.
+
+Return the **minimum** total cost to cut the entire cake into `1 x 1` pieces.
+
+**Example 1:**
+
+**Input:** m = 3, n = 2, horizontalCut = [1,3], verticalCut = [5]
+
+**Output:** 13
+
+**Explanation:**
+
+![](https://assets.leetcode.com/uploads/2024/06/04/ezgifcom-animated-gif-maker-1.gif)
+
+*   Perform a cut on the vertical line 0 with cost 5, current total cost is 5.
+*   Perform a cut on the horizontal line 0 on `3 x 1` subgrid with cost 1.
+*   Perform a cut on the horizontal line 0 on `3 x 1` subgrid with cost 1.
+*   Perform a cut on the horizontal line 1 on `2 x 1` subgrid with cost 3.
+*   Perform a cut on the horizontal line 1 on `2 x 1` subgrid with cost 3.
+
+The total cost is `5 + 1 + 1 + 3 + 3 = 13`.
+
+**Example 2:**
+
+**Input:** m = 2, n = 2, horizontalCut = [7], verticalCut = [4]
+
+**Output:** 15
+
+**Explanation:**
+
+*   Perform a cut on the horizontal line 0 with cost 7.
+*   Perform a cut on the vertical line 0 on `1 x 2` subgrid with cost 4.
+*   Perform a cut on the vertical line 0 on `1 x 2` subgrid with cost 4.
+
+The total cost is `7 + 4 + 4 = 15`.
+
+**Constraints:**
+
+*   `1 <= m, n <= 20`
+*   `horizontalCut.length == m - 1`
+*   `verticalCut.length == n - 1`
+*   <code>1 <= horizontalCut[i], verticalCut[i] <= 10<sup>3</sup></code>

src/main/kotlin/g3201_3300/s3219_minimum_cost_for_cutting_cake_ii/Solution.kt

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+package g3201_3300.s3219_minimum_cost_for_cutting_cake_ii
+
+// #Hard #Array #Sorting #Greedy #2024_07_19_Time_776_ms_(100.00%)_Space_66.8_MB_(96.88%)
+
+class Solution {
+    fun minimumCost(m: Int, n: Int, horizontalCut: IntArray, verticalCut: IntArray): Long {
+        val horizontalCounts = IntArray(N)
+        val verticalCounts = IntArray(N)
+        var max = 0
+        for (x in horizontalCut) {
+            if (x > max) {
+                max = x
+            }
+            horizontalCounts[x]++
+        }
+        for (x in verticalCut) {
+            if (x > max) {
+                max = x
+            }
+            verticalCounts[x]++
+        }
+        var ans: Long = 0
+        var horizontalCount = 1
+        var verticalCount = 1
+        for (x in max downTo 1) {
+            ans += horizontalCounts[x].toLong() * x * horizontalCount
+            verticalCount += horizontalCounts[x]
+            horizontalCounts[x] = 0
+            ans += verticalCounts[x].toLong() * x * verticalCount
+            horizontalCount += verticalCounts[x]
+            verticalCounts[x] = 0
+        }
+        return ans
+    }
+
+    companion object {
+        private const val N = 1001
+    }
+}

src/main/kotlin/g3201_3300/s3219_minimum_cost_for_cutting_cake_ii/readme.md

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+3219\. Minimum Cost for Cutting Cake II
+
+Hard
+
+There is an `m x n` cake that needs to be cut into `1 x 1` pieces.
+
+You are given integers `m`, `n`, and two arrays:
+
+*   `horizontalCut` of size `m - 1`, where `horizontalCut[i]` represents the cost to cut along the horizontal line `i`.
+*   `verticalCut` of size `n - 1`, where `verticalCut[j]` represents the cost to cut along the vertical line `j`.
+
+In one operation, you can choose any piece of cake that is not yet a `1 x 1` square and perform one of the following cuts:
+
+1.  Cut along a horizontal line `i` at a cost of `horizontalCut[i]`.
+2.  Cut along a vertical line `j` at a cost of `verticalCut[j]`.
+
+After the cut, the piece of cake is divided into two distinct pieces.
+
+The cost of a cut depends only on the initial cost of the line and does not change.
+
+Return the **minimum** total cost to cut the entire cake into `1 x 1` pieces.
+
+**Example 1:**
+
+**Input:** m = 3, n = 2, horizontalCut = [1,3], verticalCut = [5]
+
+**Output:** 13
+
+**Explanation:**
+
+![](https://assets.leetcode.com/uploads/2024/06/04/ezgifcom-animated-gif-maker-1.gif)
+
+*   Perform a cut on the vertical line 0 with cost 5, current total cost is 5.
+*   Perform a cut on the horizontal line 0 on `3 x 1` subgrid with cost 1.
+*   Perform a cut on the horizontal line 0 on `3 x 1` subgrid with cost 1.
+*   Perform a cut on the horizontal line 1 on `2 x 1` subgrid with cost 3.
+*   Perform a cut on the horizontal line 1 on `2 x 1` subgrid with cost 3.
+
+The total cost is `5 + 1 + 1 + 3 + 3 = 13`.
+
+**Example 2:**
+
+**Input:** m = 2, n = 2, horizontalCut = [7], verticalCut = [4]
+
+**Output:** 15
+
+**Explanation:**
+
+*   Perform a cut on the horizontal line 0 with cost 7.
+*   Perform a cut on the vertical line 0 on `1 x 2` subgrid with cost 4.
+*   Perform a cut on the vertical line 0 on `1 x 2` subgrid with cost 4.
+
+The total cost is `7 + 4 + 4 = 15`.
+
+**Constraints:**
+
+*   <code>1 <= m, n <= 10<sup>5</sup></code>
+*   `horizontalCut.length == m - 1`
+*   `verticalCut.length == n - 1`
+*   <code>1 <= horizontalCut[i], verticalCut[i] <= 10<sup>3</sup></code>