Added tasks 3280-3283

Author: javadev

README.md

@@ -1816,6 +1816,10 @@
 
 | #    |      Title     | Difficulty  | Tag         | Time, ms | Time, %
 |------|----------------|-------------|-------------|----------|--------
+| 3283 |[Maximum Number of Moves to Kill All Pawns](src/main/kotlin/g3201_3300/s3283_maximum_number_of_moves_to_kill_all_pawns)| Hard | Array, Math, Breadth_First_Search, Bit_Manipulation, Bitmask, Game_Theory | 638 | 100.00
+| 3282 |[Reach End of Array With Max Score](src/main/kotlin/g3201_3300/s3282_reach_end_of_array_with_max_score)| Medium | Array, Greedy | 789 | 90.91
+| 3281 |[Maximize Score of Numbers in Ranges](src/main/kotlin/g3201_3300/s3281_maximize_score_of_numbers_in_ranges)| Medium | Array, Sorting, Greedy, Binary_Search | 710 | 88.24
+| 3280 |[Convert Date to Binary](src/main/kotlin/g3201_3300/s3280_convert_date_to_binary)| Easy | String, Math | 174 | 79.31
 | 3277 |[Maximum XOR Score Subarray Queries](src/main/kotlin/g3201_3300/s3277_maximum_xor_score_subarray_queries)| Hard | Array, Dynamic_Programming | 1269 | 100.00
 | 3276 |[Select Cells in Grid With Maximum Score](src/main/kotlin/g3201_3300/s3276_select_cells_in_grid_with_maximum_score)| Hard | Array, Dynamic_Programming, Matrix, Bit_Manipulation, Bitmask | 213 | 92.31
 | 3275 |[K-th Nearest Obstacle Queries](src/main/kotlin/g3201_3300/s3275_k_th_nearest_obstacle_queries)| Medium | Array, Heap_Priority_Queue | 1277 | 100.00

src/main/kotlin/g3201_3300/s3280_convert_date_to_binary/readme.md

@@ -0,0 +1,62 @@
+[![](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)
+
+## 3280\. Convert Date to Binary
+
+Easy
+
+You are given a string `date` representing a Gregorian calendar date in the `yyyy-mm-dd` format.
+
+`date` can be written in its binary representation obtained by converting year, month, and day to their binary representations without any leading zeroes and writing them down in `year-month-day` format.
+
+Return the **binary** representation of `date`.
+
+**Example 1:**
+
+**Input:** date = "2080-02-29"
+
+**Output:** "100000100000-10-11101"
+
+**Explanation:**
+
+100000100000, 10, and 11101 are the binary representations of 2080, 02, and 29 respectively.
+
+**Example 2:**
+
+**Input:** date = "1900-01-01"
+
+**Output:** "11101101100-1-1"
+
+**Explanation:**
+
+11101101100, 1, and 1 are the binary representations of 1900, 1, and 1 respectively.
+
+**Constraints:**
+
+*   `date.length == 10`
+*   `date[4] == date[7] == '-'`, and all other `date[i]`'s are digits.
+*   The input is generated such that `date` represents a valid Gregorian calendar date between Jan 1<sup>st</sup>, 1900 and Dec 31<sup>st</sup>, 2100 (both inclusive).
+
+## Solution
+
+```kotlin
+class Solution {
+    fun convertDateToBinary(dat: String): String {
+        val str = StringBuilder()
+        val res = StringBuilder()
+        for (c in dat.toCharArray()) {
+            if (c.isDigit()) {
+                str.append(c)
+            } else if (c == '-') {
+                res.append(str.toString().toInt().toString(2))
+                res.append('-')
+                str.setLength(0)
+            }
+        }
+        if (str.isNotEmpty()) {
+            res.append(str.toString().toInt().toString(2))
+        }
+        return res.toString()
+    }
+}
+```

src/main/kotlin/g3201_3300/s3281_maximize_score_of_numbers_in_ranges/readme.md

@@ -0,0 +1,73 @@
+[![](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)
+
+## 3281\. Maximize Score of Numbers in Ranges
+
+Medium
+
+You are given an array of integers `start` and an integer `d`, representing `n` intervals `[start[i], start[i] + d]`.
+
+You are asked to choose `n` integers where the <code>i<sup>th</sup></code> integer must belong to the <code>i<sup>th</sup></code> interval. The **score** of the chosen integers is defined as the **minimum** absolute difference between any two integers that have been chosen.
+
+Return the **maximum** _possible score_ of the chosen integers.
+
+**Example 1:**
+
+**Input:** start = [6,0,3], d = 2
+
+**Output:** 4
+
+**Explanation:**
+
+The maximum possible score can be obtained by choosing integers: 8, 0, and 4. The score of these chosen integers is `min(|8 - 0|, |8 - 4|, |0 - 4|)` which equals 4.
+
+**Example 2:**
+
+**Input:** start = [2,6,13,13], d = 5
+
+**Output:** 5
+
+**Explanation:**
+
+The maximum possible score can be obtained by choosing integers: 2, 7, 13, and 18. The score of these chosen integers is `min(|2 - 7|, |2 - 13|, |2 - 18|, |7 - 13|, |7 - 18|, |13 - 18|)` which equals 5.
+
+**Constraints:**
+
+*   <code>2 <= start.length <= 10<sup>5</sup></code>
+*   <code>0 <= start[i] <= 10<sup>9</sup></code>
+*   <code>0 <= d <= 10<sup>9</sup></code>
+
+## Solution
+
+```kotlin
+import kotlin.math.max
+
+class Solution {
+    fun maxPossibleScore(start: IntArray, d: Int): Int {
+        start.sort()
+        val n = start.size
+        var l = 0
+        var r = start[n - 1] - start[0] + d + 1
+        while (l < r) {
+            val m = l + (r - l) / 2
+            if (isPossible(start, d, m)) {
+                l = m + 1
+            } else {
+                r = m
+            }
+        }
+        return l - 1
+    }
+
+    private fun isPossible(start: IntArray, d: Int, score: Int): Boolean {
+        var pre = start[0]
+        for (i in 1 until start.size) {
+            if (start[i] + d - pre < score) {
+                return false
+            }
+            pre = max(start[i], (pre + score))
+        }
+        return true
+    }
+}
+```

src/main/kotlin/g3201_3300/s3282_reach_end_of_array_with_max_score/readme.md

@@ -0,0 +1,57 @@
+[![](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)
+
+## 3282\. Reach End of Array With Max Score
+
+Medium
+
+You are given an integer array `nums` of length `n`.
+
+Your goal is to start at index `0` and reach index `n - 1`. You can only jump to indices **greater** than your current index.
+
+The score for a jump from index `i` to index `j` is calculated as `(j - i) * nums[i]`.
+
+Return the **maximum** possible **total score** by the time you reach the last index.
+
+**Example 1:**
+
+**Input:** nums = [1,3,1,5]
+
+**Output:** 7
+
+**Explanation:**
+
+First, jump to index 1 and then jump to the last index. The final score is `1 * 1 + 2 * 3 = 7`.
+
+**Example 2:**
+
+**Input:** nums = [4,3,1,3,2]
+
+**Output:** 16
+
+**Explanation:**
+
+Jump directly to the last index. The final score is `4 * 4 = 16`.
+
+**Constraints:**
+
+*   <code>1 <= nums.length <= 10<sup>5</sup></code>
+*   <code>1 <= nums[i] <= 10<sup>5</sup></code>
+
+## Solution
+
+```kotlin
+import kotlin.math.max
+
+class Solution {
+    fun findMaximumScore(nums: List<Int>): Long {
+        var res: Long = 0
+        var ma: Long = 0
+        for (num in nums) {
+            res += ma
+            ma = max(ma, num.toLong())
+        }
+        return res
+    }
+}
+```

src/main/kotlin/g3201_3300/s3283_maximum_number_of_moves_to_kill_all_pawns/readme.md

@@ -0,0 +1,159 @@
+[![](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)
+
+## 3283\. Maximum Number of Moves to Kill All Pawns
+
+Hard
+
+There is a `50 x 50` chessboard with **one** knight and some pawns on it. You are given two integers `kx` and `ky` where `(kx, ky)` denotes the position of the knight, and a 2D array `positions` where <code>positions[i] = [x<sub>i</sub>, y<sub>i</sub>]</code> denotes the position of the pawns on the chessboard.
+
+Alice and Bob play a _turn-based_ game, where Alice goes first. In each player's turn:
+
+*   The player _selects_ a pawn that still exists on the board and captures it with the knight in the **fewest** possible **moves**. **Note** that the player can select **any** pawn, it **might not** be one that can be captured in the **least** number of moves.
+*   In the process of capturing the _selected_ pawn, the knight **may** pass other pawns **without** capturing them. **Only** the _selected_ pawn can be captured in _this_ turn.
+
+Alice is trying to **maximize** the **sum** of the number of moves made by _both_ players until there are no more pawns on the board, whereas Bob tries to **minimize** them.
+
+Return the **maximum** _total_ number of moves made during the game that Alice can achieve, assuming both players play **optimally**.
+
+Note that in one **move,** a chess knight has eight possible positions it can move to, as illustrated below. Each move is two cells in a cardinal direction, then one cell in an orthogonal direction.
+
+![](https://assets.leetcode.com/uploads/2024/08/01/chess_knight.jpg)
+
+**Example 1:**
+
+**Input:** kx = 1, ky = 1, positions = \[\[0,0]]
+
+**Output:** 4
+
+**Explanation:**
+
+![](https://assets.leetcode.com/uploads/2024/08/16/gif3.gif)
+
+The knight takes 4 moves to reach the pawn at `(0, 0)`.
+
+**Example 2:**
+
+**Input:** kx = 0, ky = 2, positions = \[\[1,1],[2,2],[3,3]]
+
+**Output:** 8
+
+**Explanation:**
+
+**![](https://assets.leetcode.com/uploads/2024/08/16/gif4.gif)**
+
+*   Alice picks the pawn at `(2, 2)` and captures it in two moves: `(0, 2) -> (1, 4) -> (2, 2)`.
+*   Bob picks the pawn at `(3, 3)` and captures it in two moves: `(2, 2) -> (4, 1) -> (3, 3)`.
+*   Alice picks the pawn at `(1, 1)` and captures it in four moves: `(3, 3) -> (4, 1) -> (2, 2) -> (0, 3) -> (1, 1)`.
+
+**Example 3:**
+
+**Input:** kx = 0, ky = 0, positions = \[\[1,2],[2,4]]
+
+**Output:** 3
+
+**Explanation:**
+
+*   Alice picks the pawn at `(2, 4)` and captures it in two moves: `(0, 0) -> (1, 2) -> (2, 4)`. Note that the pawn at `(1, 2)` is not captured.
+*   Bob picks the pawn at `(1, 2)` and captures it in one move: `(2, 4) -> (1, 2)`.
+
+**Constraints:**
+
+*   `0 <= kx, ky <= 49`
+*   `1 <= positions.length <= 15`
+*   `positions[i].length == 2`
+*   `0 <= positions[i][0], positions[i][1] <= 49`
+*   All `positions[i]` are unique.
+*   The input is generated such that `positions[i] != [kx, ky]` for all `0 <= i < positions.length`.
+
+## Solution
+
+```kotlin
+import java.util.LinkedList
+import java.util.Queue
+import kotlin.math.max
+import kotlin.math.min
+
+class Solution {
+    private lateinit var distances: Array<IntArray>
+    private lateinit var memo: Array<Array<Int?>?>
+
+    fun maxMoves(kx: Int, ky: Int, positions: Array<IntArray>): Int {
+        val n = positions.size
+        distances = Array<IntArray>(n + 1) { IntArray(n + 1) { 0 } }
+        memo = Array<Array<Int?>?>(n + 1) { arrayOfNulls<Int>(1 shl n) }
+        // Calculate distances between all pairs of positions (including knight's initial position)
+        for (i in 0 until n) {
+            distances[n][i] = calculateMoves(kx, ky, positions[i][0], positions[i][1])
+            for (j in i + 1 until n) {
+                val dist =
+                    calculateMoves(
+                        positions[i][0], positions[i][1], positions[j][0], positions[j][1]
+                    )
+                distances[j][i] = dist
+                distances[i][j] = distances[j][i]
+            }
+        }
+        return minimax(n, (1 shl n) - 1, true)
+    }
+
+    private fun minimax(lastPos: Int, remainingPawns: Int, isAlice: Boolean): Int {
+        if (remainingPawns == 0) {
+            return 0
+        }
+        if (memo[lastPos]!![remainingPawns] != null) {
+            return memo[lastPos]!![remainingPawns]!!
+        }
+        var result = if (isAlice) 0 else Int.Companion.MAX_VALUE
+        for (i in 0 until distances.size - 1) {
+            if ((remainingPawns and (1 shl i)) != 0) {
+                val newRemainingPawns = remainingPawns and (1 shl i).inv()
+                val moveValue = distances[lastPos][i] + minimax(i, newRemainingPawns, !isAlice)
+                result = if (isAlice) {
+                    max(result, moveValue)
+                } else {
+                    min(result, moveValue)
+                }
+            }
+        }
+        memo[lastPos]!![remainingPawns] = result
+        return result
+    }
+
+    private fun calculateMoves(x1: Int, y1: Int, x2: Int, y2: Int): Int {
+        if (x1 == x2 && y1 == y2) {
+            return 0
+        }
+        val visited = Array<BooleanArray?>(50) { BooleanArray(50) }
+        val queue: Queue<IntArray> = LinkedList<IntArray>()
+        queue.offer(intArrayOf(x1, y1, 0))
+        visited[x1]!![y1] = true
+        while (queue.isNotEmpty()) {
+            val current = queue.poll()
+            val x = current[0]
+            val y = current[1]
+            val moves = current[2]
+            for (move in KNIGHT_MOVES) {
+                val nx = x + move[0]
+                val ny = y + move[1]
+                if (nx == x2 && ny == y2) {
+                    return moves + 1
+                }
+                if (nx >= 0 && nx < 50 && ny >= 0 && ny < 50 && !visited[nx]!![ny]) {
+                    queue.offer(intArrayOf(nx, ny, moves + 1))
+                    visited[nx]!![ny] = true
+                }
+            }
+        }
+        // Should never reach here if input is valid
+        return -1
+    }
+
+    companion object {
+        private val KNIGHT_MOVES = arrayOf<IntArray>(
+            intArrayOf(-2, -1), intArrayOf(-2, 1), intArrayOf(-1, -2), intArrayOf(-1, 2),
+            intArrayOf(1, -2), intArrayOf(1, 2), intArrayOf(2, -1), intArrayOf(2, 1)
+        )
+    }
+}
+```