Added tasks 3354-3357

src/main/java/g3301_3400/s3354_make_array_elements_equal_to_zero/Solution.java

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+package g3301_3400.s3354_make_array_elements_equal_to_zero;
+
+// #Easy #Array #Simulation #Prefix_Sum #2024_11_19_Time_1_ms_(95.09%)_Space_41.9_MB_(92.55%)
+
+public class Solution {
+    public int countValidSelections(int[] nums) {
+        int[] rightSum = new int[nums.length];
+        int[] leftSum = new int[nums.length];
+        int result = 0;
+        leftSum[0] = 0;
+        rightSum[nums.length - 1] = 0;
+        for (int i = 1; i < nums.length; i++) {
+            leftSum[i] = leftSum[i - 1] + nums[i - 1];
+        }
+        for (int j = nums.length - 2; j >= 0; j--) {
+            rightSum[j] = rightSum[j + 1] + nums[j + 1];
+        }
+        for (int k = 0; k < nums.length; k++) {
+            if (nums[k] == 0 && Math.abs(rightSum[k] - leftSum[k]) == 1) {
+                result++;
+            }
+            if (nums[k] == 0 && Math.abs(rightSum[k] - leftSum[k]) == 0) {
+                result += 2;
+            }
+        }
+        return result;
+    }
+}

src/main/java/g3301_3400/s3354_make_array_elements_equal_to_zero/readme.md

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+3354\. Make Array Elements Equal to Zero
+
+Easy
+
+You are given an integer array `nums`.
+
+Start by selecting a starting position `curr` such that `nums[curr] == 0`, and choose a movement **direction** of either left or right.
+
+After that, you repeat the following process:
+
+*   If `curr` is out of the range `[0, n - 1]`, this process ends.
+*   If `nums[curr] == 0`, move in the current direction by **incrementing** `curr` if you are moving right, or **decrementing** `curr` if you are moving left.
+*   Else if `nums[curr] > 0`:
+    *   Decrement `nums[curr]` by 1.
+    *   **Reverse** your movement direction (left becomes right and vice versa).
+    *   Take a step in your new direction.
+
+A selection of the initial position `curr` and movement direction is considered **valid** if every element in `nums` becomes 0 by the end of the process.
+
+Return the number of possible **valid** selections.
+
+**Example 1:**
+
+**Input:** nums = [1,0,2,0,3]
+
+**Output:** 2
+
+**Explanation:**
+
+The only possible valid selections are the following:
+
+*   Choose `curr = 3`, and a movement direction to the left.
+    *   <code>[1,0,2,**<ins>0</ins>**,3] -> [1,0,**<ins>2</ins>**,0,3] -> [1,0,1,**<ins>0</ins>**,3] -> [1,0,1,0,**<ins>3</ins>**] -> [1,0,1,**<ins>0</ins>**,2] -> [1,0,**<ins>1</ins>**,0,2] -> [1,0,0,**<ins>0</ins>**,2] -> [1,0,0,0,**<ins>2</ins>**] -> [1,0,0,**<ins>0</ins>**,1] -> [1,0,**<ins>0</ins>**,0,1] -> [1,**<ins>0</ins>**,0,0,1] -> [**<ins>1</ins>**,0,0,0,1] -> [0,**<ins>0</ins>**,0,0,1] -> [0,0,**<ins>0</ins>**,0,1] -> [0,0,0,**<ins>0</ins>**,1] -> [0,0,0,0,**<ins>1</ins>**] -> [0,0,0,0,0]</code>.
+*   Choose `curr = 3`, and a movement direction to the right.
+    *   <code>[1,0,2,**<ins>0</ins>**,3] -> [1,0,2,0,**<ins>3</ins>**] -> [1,0,2,**<ins>0</ins>**,2] -> [1,0,**<ins>2</ins>**,0,2] -> [1,0,1,**<ins>0</ins>**,2] -> [1,0,1,0,**<ins>2</ins>**] -> [1,0,1,**<ins>0</ins>**,1] -> [1,0,**<ins>1</ins>**,0,1] -> [1,0,0,**<ins>0</ins>**,1] -> [1,0,0,0,**<ins>1</ins>**] -> [1,0,0,**<ins>0</ins>**,0] -> [1,0,**<ins>0</ins>**,0,0] -> [1,**<ins>0</ins>**,0,0,0] -> [**<ins>1</ins>**,0,0,0,0] -> [0,0,0,0,0].</code>
+
+**Example 2:**
+
+**Input:** nums = [2,3,4,0,4,1,0]
+
+**Output:** 0
+
+**Explanation:**
+
+There are no possible valid selections.
+
+**Constraints:**
+
+*   `1 <= nums.length <= 100`
+*   `0 <= nums[i] <= 100`
+*   There is at least one element `i` where `nums[i] == 0`.

src/main/java/g3301_3400/s3355_zero_array_transformation_i/Solution.java

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+package g3301_3400.s3355_zero_array_transformation_i;
+
+// #Medium #Array #Prefix_Sum #2024_11_19_Time_3_ms_(91.34%)_Space_96_MB_(17.22%)
+
+public class Solution {
+    public boolean isZeroArray(int[] nums, int[][] queries) {
+        int n = nums.length;
+        int sum = 0;
+        for (int num : nums) {
+            sum += num;
+        }
+        if (sum == 0) {
+            return true;
+        }
+        int[] diff = new int[n + 1];
+        for (int[] q : queries) {
+            int low = q[0];
+            int high = q[1];
+            diff[low] -= 1;
+            if (high + 1 < n) {
+                diff[high + 1] += 1;
+            }
+        }
+        for (int i = 0; i < n; i++) {
+            if (i > 0) {
+                diff[i] += diff[i - 1];
+            }
+            nums[i] += diff[i];
+            sum += diff[i];
+            if (nums[i] > 0) {
+                return false;
+            }
+        }
+        return sum <= 0;
+    }
+}

src/main/java/g3301_3400/s3355_zero_array_transformation_i/readme.md

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+3355\. Zero Array Transformation I
+
+Medium
+
+You are given an integer array `nums` of length `n` and a 2D array `queries`, where <code>queries[i] = [l<sub>i</sub>, r<sub>i</sub>]</code>.
+
+For each `queries[i]`:
+
+*   Select a subset of indices within the range <code>[l<sub>i</sub>, r<sub>i</sub>]</code> in `nums`.
+*   Decrement the values at the selected indices by 1.
+
+A **Zero Array** is an array where all elements are equal to 0.
+
+Return `true` if it is _possible_ to transform `nums` into a **Zero Array** after processing all the queries sequentially, otherwise return `false`.
+
+A **subset** of an array is a selection of elements (possibly none) of the array.
+
+**Example 1:**
+
+**Input:** nums = [1,0,1], queries = [[0,2]]
+
+**Output:** true
+
+**Explanation:**
+
+*   **For i = 0:**
+    *   Select the subset of indices as `[0, 2]` and decrement the values at these indices by 1.
+    *   The array will become `[0, 0, 0]`, which is a Zero Array.
+
+**Example 2:**
+
+**Input:** nums = [4,3,2,1], queries = [[1,3],[0,2]]
+
+**Output:** false
+
+**Explanation:**
+
+*   **For i = 0:**
+    *   Select the subset of indices as `[1, 2, 3]` and decrement the values at these indices by 1.
+    *   The array will become `[4, 2, 1, 0]`.
+*   **For i = 1:**
+    *   Select the subset of indices as `[0, 1, 2]` and decrement the values at these indices by 1.
+    *   The array will become `[3, 1, 0, 0]`, which is not a Zero Array.
+
+**Constraints:**
+
+*   <code>1 <= nums.length <= 10<sup>5</sup></code>
+*   <code>0 <= nums[i] <= 10<sup>5</sup></code>
+*   <code>1 <= queries.length <= 10<sup>5</sup></code>
+*   `queries[i].length == 2`
+*   <code>0 <= l<sub>i</sub> <= r<sub>i</sub> < nums.length</code>

src/main/java/g3301_3400/s3356_zero_array_transformation_ii/Solution.java

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+package g3301_3400.s3356_zero_array_transformation_ii;
+
+// #Medium #Array #Binary_Search #Prefix_Sum #2024_11_19_Time_4_ms_(93.46%)_Space_118.5_MB_(13.87%)
+
+public class Solution {
+    public int minZeroArray(int[] nums, int[][] queries) {
+        int[] diff = new int[nums.length];
+        int idx = 0;
+        int d = 0;
+        for (int i = 0; i < nums.length; i++) {
+            d += diff[i];
+            while (nums[i] + d > 0 && idx < queries.length) {
+                int[] q = queries[idx];
+                if (i >= q[0] && i <= q[1]) {
+                    d -= q[2];
+                }
+                diff[q[0]] -= q[2];
+                if (q[1] + 1 < nums.length) {
+                    diff[q[1] + 1] += q[2];
+                }
+                idx++;
+            }
+            if (nums[i] + d > 0) {
+                return -1;
+            }
+        }
+        return idx;
+    }
+}

src/main/java/g3301_3400/s3356_zero_array_transformation_ii/readme.md

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+3356\. Zero Array Transformation II
+
+Medium
+
+You are given an integer array `nums` of length `n` and a 2D array `queries` where <code>queries[i] = [l<sub>i</sub>, r<sub>i</sub>, val<sub>i</sub>]</code>.
+
+Each `queries[i]` represents the following action on `nums`:
+
+*   Decrement the value at each index in the range <code>[l<sub>i</sub>, r<sub>i</sub>]</code> in `nums` by **at most** <code>val<sub>i</sub></code>.
+*   The amount by which each value is decremented can be chosen **independently** for each index.
+
+A **Zero Array** is an array with all its elements equal to 0.
+
+Return the **minimum** possible **non-negative** value of `k`, such that after processing the first `k` queries in **sequence**, `nums` becomes a **Zero Array**. If no such `k` exists, return -1.
+
+**Example 1:**
+
+**Input:** nums = [2,0,2], queries = [[0,2,1],[0,2,1],[1,1,3]]
+
+**Output:** 2
+
+**Explanation:**
+
+*   **For i = 0 (l = 0, r = 2, val = 1):**
+    *   Decrement values at indices `[0, 1, 2]` by `[1, 0, 1]` respectively.
+    *   The array will become `[1, 0, 1]`.
+*   **For i = 1 (l = 0, r = 2, val = 1):**
+    *   Decrement values at indices `[0, 1, 2]` by `[1, 0, 1]` respectively.
+    *   The array will become `[0, 0, 0]`, which is a Zero Array. Therefore, the minimum value of `k` is 2.
+
+**Example 2:**
+
+**Input:** nums = [4,3,2,1], queries = [[1,3,2],[0,2,1]]
+
+**Output:** \-1
+
+**Explanation:**
+
+*   **For i = 0 (l = 1, r = 3, val = 2):**
+    *   Decrement values at indices `[1, 2, 3]` by `[2, 2, 1]` respectively.
+    *   The array will become `[4, 1, 0, 0]`.
+*   **For i = 1 (l = 0, r = 2, val \= 1):**
+    *   Decrement values at indices `[0, 1, 2]` by `[1, 1, 0]` respectively.
+    *   The array will become `[3, 0, 0, 0]`, which is not a Zero Array.
+
+**Constraints:**
+
+*   <code>1 <= nums.length <= 10<sup>5</sup></code>
+*   <code>0 <= nums[i] <= 5 * 10<sup>5</sup></code>
+*   <code>1 <= queries.length <= 10<sup>5</sup></code>
+*   `queries[i].length == 3`
+*   <code>0 <= l<sub>i</sub> <= r<sub>i</sub> < nums.length</code>
+*   <code>1 <= val<sub>i</sub> <= 5</code>

src/main/java/g3301_3400/s3357_minimize_the_maximum_adjacent_element_difference/Solution.java

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+package g3301_3400.s3357_minimize_the_maximum_adjacent_element_difference;
+
+// #Hard #Array #Greedy #Binary_Search #2024_11_19_Time_5_ms_(100.00%)_Space_59.2_MB_(29.41%)
+
+public class Solution {
+    public int minDifference(int[] nums) {
+        int n = nums.length;
+        int maxAdj = 0;
+        int mina = Integer.MAX_VALUE;
+        int maxb = Integer.MIN_VALUE;
+        for (int i = 0; i < n - 1; ++i) {
+            int a = nums[i];
+            int b = nums[i + 1];
+            if (a > 0 && b > 0) {
+                maxAdj = Math.max(maxAdj, Math.abs(a - b));
+            } else if (a > 0 || b > 0) {
+                mina = Math.min(mina, Math.max(a, b));
+                maxb = Math.max(maxb, Math.max(a, b));
+            }
+        }
+        int res = 0;
+        for (int i = 0; i < n; ++i) {
+            if ((i > 0 && nums[i - 1] == -1) || nums[i] > 0) {
+                continue;
+            }
+            int j = i;
+            while (j < n && nums[j] == -1) {
+                j++;
+            }
+            int a = Integer.MAX_VALUE;
+            int b = Integer.MIN_VALUE;
+            if (i > 0) {
+                a = Math.min(a, nums[i - 1]);
+                b = Math.max(b, nums[i - 1]);
+            }
+            if (j < n) {
+                a = Math.min(a, nums[j]);
+                b = Math.max(b, nums[j]);
+            }
+            if (a <= b) {
+                if (j - i == 1) {
+                    res = Math.max(res, Math.min(maxb - a, b - mina));
+                } else {
+                    res =
+                            Math.max(
+                                    res,
+                                    Math.min(
+                                            maxb - a,
+                                            Math.min(b - mina, (maxb - mina + 2) / 3 * 2)));
+                }
+            }
+        }
+        return Math.max(maxAdj, (res + 1) / 2);
+    }
+}

src/main/java/g3301_3400/s3357_minimize_the_maximum_adjacent_element_difference/readme.md

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+3357\. Minimize the Maximum Adjacent Element Difference
+
+Hard
+
+You are given an array of integers `nums`. Some values in `nums` are **missing** and are denoted by -1.
+
+You can choose a pair of **positive** integers `(x, y)` **exactly once** and replace each **missing** element with _either_ `x` or `y`.
+
+You need to **minimize** the **maximum** **absolute difference** between _adjacent_ elements of `nums` after replacements.
+
+Return the **minimum** possible difference.
+
+**Example 1:**
+
+**Input:** nums = [1,2,-1,10,8]
+
+**Output:** 4
+
+**Explanation:**
+
+By choosing the pair as `(6, 7)`, nums can be changed to `[1, 2, 6, 10, 8]`.
+
+The absolute differences between adjacent elements are:
+
+*   `|1 - 2| == 1`
+*   `|2 - 6| == 4`
+*   `|6 - 10| == 4`
+*   `|10 - 8| == 2`
+
+**Example 2:**
+
+**Input:** nums = [-1,-1,-1]
+
+**Output:** 0
+
+**Explanation:**
+
+By choosing the pair as `(4, 4)`, nums can be changed to `[4, 4, 4]`.
+
+**Example 3:**
+
+**Input:** nums = [-1,10,-1,8]
+
+**Output:** 1
+
+**Explanation:**
+
+By choosing the pair as `(11, 9)`, nums can be changed to `[11, 10, 9, 8]`.
+
+**Constraints:**
+
+*   <code>2 <= nums.length <= 10<sup>5</sup></code>
+*   `nums[i]` is either -1 or in the range <code>[1, 10<sup>9</sup>]</code>.

src/test/java/g3301_3400/s3354_make_array_elements_equal_to_zero/SolutionTest.java

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+package g3301_3400.s3354_make_array_elements_equal_to_zero;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class SolutionTest {
+    @Test
+    void countValidSelections() {
+        assertThat(new Solution().countValidSelections(new int[] {1, 0, 2, 0, 3}), equalTo(2));
+    }
+
+    @Test
+    void countValidSelections2() {
+        assertThat(
+                new Solution().countValidSelections(new int[] {2, 3, 4, 0, 4, 1, 0}), equalTo(0));
+    }
+
+    @Test
+    void countValidSelections3() {
+        assertThat(
+                new Solution()
+                        .countValidSelections(new int[] {16, 13, 10, 0, 0, 0, 10, 6, 7, 8, 7}),
+                equalTo(3));
+    }
+}