Added tasks 3280-3283

src/main/java/g3201_3300/s3280_convert_date_to_binary/Solution.java

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+package g3201_3300.s3280_convert_date_to_binary;
+
+// #Easy #String #Math #2024_09_09_Time_3_ms_(100.00%)_Space_42.4_MB_(50.00%)
+
+public class Solution {
+    private String helper(String str) {
+        return Integer.toBinaryString(Integer.parseInt(str));
+    }
+
+    public String convertDateToBinary(String date) {
+        StringBuilder sb = new StringBuilder();
+        for (String str : date.split("-")) {
+            sb.append(helper(str));
+            sb.append("-");
+        }
+        sb.deleteCharAt(sb.length() - 1);
+        return sb.toString();
+    }
+}

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

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+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).

src/main/java/g3201_3300/s3281_maximize_score_of_numbers_in_ranges/Solution.java

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+package g3201_3300.s3281_maximize_score_of_numbers_in_ranges;
+
+// #Medium #Array #Sorting #Greedy #Binary_Search
+// #2024_09_09_Time_47_ms_(100.00%)_Space_58.3_MB_(100.00%)
+
+import java.util.Arrays;
+
+public class Solution {
+    public int maxPossibleScore(int[] start, int d) {
+        Arrays.sort(start);
+        int n = start.length;
+        int l = 0;
+        int r = start[n - 1] - start[0] + d + 1;
+        while (l < r) {
+            int m = l + (r - l) / 2;
+            if (isPossible(start, d, m)) {
+                l = m + 1;
+            } else {
+                r = m;
+            }
+        }
+        return l - 1;
+    }
+
+    private boolean isPossible(int[] start, int d, int score) {
+        int pre = start[0];
+        for (int i = 1; i < start.length; i++) {
+            if (start[i] + d - pre < score) {
+                return false;
+            }
+            pre = Math.max(start[i], pre + score);
+        }
+        return true;
+    }
+}

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

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+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>

src/main/java/g3201_3300/s3282_reach_end_of_array_with_max_score/Solution.java

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+package g3201_3300.s3282_reach_end_of_array_with_max_score;
+
+// #Medium #Array #Greedy #2024_09_09_Time_9_ms_(100.00%)_Space_63.2_MB_(100.00%)
+
+import java.util.List;
+
+public class Solution {
+    public long findMaximumScore(List<Integer> nums) {
+        long res = 0;
+        long ma = 0;
+        for (int num : nums) {
+            res += ma;
+            ma = Math.max(ma, num);
+        }
+        return res;
+    }
+}

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

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+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>

src/main/java/g3201_3300/s3283_maximum_number_of_moves_to_kill_all_pawns/Solution.java

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+package g3201_3300.s3283_maximum_number_of_moves_to_kill_all_pawns;
+
+// #Hard #Array #Math #Breadth_First_Search #Bit_Manipulation #Bitmask #Game_Theory
+// #2024_09_09_Time_250_ms_(98.43%)_Space_50.1_MB_(66.27%)
+
+import java.util.LinkedList;
+import java.util.Queue;
+
+public class Solution {
+    private static final int[][] KNIGHT_MOVES = {
+        {-2, -1}, {-2, 1}, {-1, -2}, {-1, 2},
+        {1, -2}, {1, 2}, {2, -1}, {2, 1}
+    };
+    private int[][] distances;
+    private Integer[][] memo;
+
+    public int maxMoves(int kx, int ky, int[][] positions) {
+        int n = positions.length;
+        distances = new int[n + 1][n + 1];
+        memo = new Integer[n + 1][1 << n];
+        // Calculate distances between all pairs of positions (including knight's initial position)
+        for (int i = 0; i < n; i++) {
+            distances[n][i] = calculateMoves(kx, ky, positions[i][0], positions[i][1]);
+            for (int j = i + 1; j < n; j++) {
+                int dist =
+                        calculateMoves(
+                                positions[i][0], positions[i][1], positions[j][0], positions[j][1]);
+                distances[i][j] = distances[j][i] = dist;
+            }
+        }
+        return minimax(n, (1 << n) - 1, true);
+    }
+
+    private int minimax(int lastPos, int remainingPawns, boolean isAlice) {
+        if (remainingPawns == 0) {
+            return 0;
+        }
+        if (memo[lastPos][remainingPawns] != null) {
+            return memo[lastPos][remainingPawns];
+        }
+        int result = isAlice ? 0 : Integer.MAX_VALUE;
+        for (int i = 0; i < distances.length - 1; i++) {
+            if ((remainingPawns & (1 << i)) != 0) {
+                int newRemainingPawns = remainingPawns & ~(1 << i);
+                int moveValue = distances[lastPos][i] + minimax(i, newRemainingPawns, !isAlice);
+
+                if (isAlice) {
+                    result = Math.max(result, moveValue);
+                } else {
+                    result = Math.min(result, moveValue);
+                }
+            }
+        }
+        memo[lastPos][remainingPawns] = result;
+        return result;
+    }
+
+    private int calculateMoves(int x1, int y1, int x2, int y2) {
+        if (x1 == x2 && y1 == y2) {
+            return 0;
+        }
+        boolean[][] visited = new boolean[50][50];
+        Queue<int[]> queue = new LinkedList<>();
+        queue.offer(new int[] {x1, y1, 0});
+        visited[x1][y1] = true;
+        while (!queue.isEmpty()) {
+            int[] current = queue.poll();
+            int x = current[0];
+            int y = current[1];
+            int moves = current[2];
+            for (int[] move : KNIGHT_MOVES) {
+                int nx = x + move[0];
+                int 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(new int[] {nx, ny, moves + 1});
+                    visited[nx][ny] = true;
+                }
+            }
+        }
+        // Should never reach here if input is valid
+        return -1;
+    }
+}

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

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+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`.

src/test/java/g3201_3300/s3280_convert_date_to_binary/SolutionTest.java

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+package g3201_3300.s3280_convert_date_to_binary;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class SolutionTest {
+    @Test
+    void convertDateToBinary() {
+        assertThat(
+                new Solution().convertDateToBinary("2080-02-29"), equalTo("100000100000-10-11101"));
+    }
+
+    @Test
+    void convertDateToBinary2() {
+        assertThat(new Solution().convertDateToBinary("1900-01-01"), equalTo("11101101100-1-1"));
+    }
+}

src/test/java/g3201_3300/s3281_maximize_score_of_numbers_in_ranges/SolutionTest.java

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+package g3201_3300.s3281_maximize_score_of_numbers_in_ranges;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class SolutionTest {
+    @Test
+    void maxPossibleScore() {
+        assertThat(new Solution().maxPossibleScore(new int[] {6, 0, 3}, 2), equalTo(4));
+    }
+
+    @Test
+    void maxPossibleScore2() {
+        assertThat(new Solution().maxPossibleScore(new int[] {2, 6, 13, 13}, 5), equalTo(5));
+    }
+}

src/test/java/g3201_3300/s3282_reach_end_of_array_with_max_score/SolutionTest.java

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+package g3201_3300.s3282_reach_end_of_array_with_max_score;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+class SolutionTest {
+    @Test
+    void findMaximumScore() {
+        assertThat(new Solution().findMaximumScore(List.of(1, 3, 1, 5)), equalTo(7L));
+    }
+
+    @Test
+    void findMaximumScore2() {
+        assertThat(new Solution().findMaximumScore(List.of(4, 3, 1, 3, 2)), equalTo(16L));
+    }
+}