Added tasks 3477-3480

src/main/kotlin/g3401_3500/s3477_fruits_into_baskets_ii/Solution.kt

@@ -0,0 +1,23 @@
+package g3401_3500.s3477_fruits_into_baskets_ii
+
+// #Easy #Array #Binary_Search #Simulation #Segment_Tree
+// #2025_03_11_Time_3_ms_(100.00%)_Space_47.78_MB_(75.61%)
+
+class Solution {
+    fun numOfUnplacedFruits(fruits: IntArray, baskets: IntArray): Int {
+        val n = fruits.size
+        var currfruits: Int
+        var count = 0
+        for (i in 0..<n) {
+            currfruits = fruits[i]
+            for (j in 0..<n) {
+                if (baskets[j] >= currfruits) {
+                    count++
+                    baskets[j] = 0
+                    break
+                }
+            }
+        }
+        return n - count
+    }
+}

src/main/kotlin/g3401_3500/s3477_fruits_into_baskets_ii/readme.md

@@ -0,0 +1,47 @@
+3477\. Fruits Into Baskets II
+
+Easy
+
+You are given two arrays of integers, `fruits` and `baskets`, each of length `n`, where `fruits[i]` represents the **quantity** of the <code>i<sup>th</sup></code> type of fruit, and `baskets[j]` represents the **capacity** of the <code>j<sup>th</sup></code> basket.
+
+From left to right, place the fruits according to these rules:
+
+*   Each fruit type must be placed in the **leftmost available basket** with a capacity **greater than or equal** to the quantity of that fruit type.
+*   Each basket can hold **only one** type of fruit.
+*   If a fruit type **cannot be placed** in any basket, it remains **unplaced**.
+
+Return the number of fruit types that remain unplaced after all possible allocations are made.
+
+**Example 1:**
+
+**Input:** fruits = [4,2,5], baskets = [3,5,4]
+
+**Output:** 1
+
+**Explanation:**
+
+*   `fruits[0] = 4` is placed in `baskets[1] = 5`.
+*   `fruits[1] = 2` is placed in `baskets[0] = 3`.
+*   `fruits[2] = 5` cannot be placed in `baskets[2] = 4`.
+
+Since one fruit type remains unplaced, we return 1.
+
+**Example 2:**
+
+**Input:** fruits = [3,6,1], baskets = [6,4,7]
+
+**Output:** 0
+
+**Explanation:**
+
+*   `fruits[0] = 3` is placed in `baskets[0] = 6`.
+*   `fruits[1] = 6` cannot be placed in `baskets[1] = 4` (insufficient capacity) but can be placed in the next available basket, `baskets[2] = 7`.
+*   `fruits[2] = 1` is placed in `baskets[1] = 4`.
+
+Since all fruits are successfully placed, we return 0.
+
+**Constraints:**
+
+*   `n == fruits.length == baskets.length`
+*   `1 <= n <= 100`
+*   `1 <= fruits[i], baskets[i] <= 1000`

src/main/kotlin/g3401_3500/s3478_choose_k_elements_with_maximum_sum/Solution.kt

@@ -0,0 +1,40 @@
+package g3401_3500.s3478_choose_k_elements_with_maximum_sum
+
+// #Medium #Array #Sorting #Heap_Priority_Queue
+// #2025_03_11_Time_151_ms_(100.00%)_Space_93.64_MB_(40.74%)
+
+import java.util.PriorityQueue
+
+class Solution {
+    fun findMaxSum(nums1: IntArray, nums2: IntArray, k: Int): LongArray {
+        val n = nums1.size
+        val ans = LongArray(n)
+        val ps = Array<Point>(n) { i -> Point(nums1[i], nums2[i], i) }
+        ps.sortWith { p1: Point, p2: Point -> p1.x.compareTo(p2.x) }
+        val pq = PriorityQueue<Int?>()
+        var s: Long = 0
+        var i = 0
+        while (i < n) {
+            var j = i
+            while (j < n && ps[j].x == ps[i].x) {
+                ans[ps[j].i] = s
+                j++
+            }
+            for (p in i..<j) {
+                val cur = ps[p].y
+                if (pq.size < k) {
+                    pq.offer(cur)
+                    s += cur.toLong()
+                } else if (cur > pq.peek()!!) {
+                    s -= pq.poll()!!.toLong()
+                    pq.offer(cur)
+                    s += cur.toLong()
+                }
+            }
+            i = j
+        }
+        return ans
+    }
+
+    private class Point(var x: Int, var y: Int, var i: Int)
+}

src/main/kotlin/g3401_3500/s3478_choose_k_elements_with_maximum_sum/readme.md

@@ -0,0 +1,43 @@
+3478\. Choose K Elements With Maximum Sum
+
+Medium
+
+You are given two integer arrays, `nums1` and `nums2`, both of length `n`, along with a positive integer `k`.
+
+For each index `i` from `0` to `n - 1`, perform the following:
+
+*   Find **all** indices `j` where `nums1[j]` is less than `nums1[i]`.
+*   Choose **at most** `k` values of `nums2[j]` at these indices to **maximize** the total sum.
+
+Return an array `answer` of size `n`, where `answer[i]` represents the result for the corresponding index `i`.
+
+**Example 1:**
+
+**Input:** nums1 = [4,2,1,5,3], nums2 = [10,20,30,40,50], k = 2
+
+**Output:** [80,30,0,80,50]
+
+**Explanation:**
+
+*   For `i = 0`: Select the 2 largest values from `nums2` at indices `[1, 2, 4]` where `nums1[j] < nums1[0]`, resulting in `50 + 30 = 80`.
+*   For `i = 1`: Select the 2 largest values from `nums2` at index `[2]` where `nums1[j] < nums1[1]`, resulting in 30.
+*   For `i = 2`: No indices satisfy `nums1[j] < nums1[2]`, resulting in 0.
+*   For `i = 3`: Select the 2 largest values from `nums2` at indices `[0, 1, 2, 4]` where `nums1[j] < nums1[3]`, resulting in `50 + 30 = 80`.
+*   For `i = 4`: Select the 2 largest values from `nums2` at indices `[1, 2]` where `nums1[j] < nums1[4]`, resulting in `30 + 20 = 50`.
+
+**Example 2:**
+
+**Input:** nums1 = [2,2,2,2], nums2 = [3,1,2,3], k = 1
+
+**Output:** [0,0,0,0]
+
+**Explanation:**
+
+Since all elements in `nums1` are equal, no indices satisfy the condition `nums1[j] < nums1[i]` for any `i`, resulting in 0 for all positions.
+
+**Constraints:**
+
+*   `n == nums1.length == nums2.length`
+*   <code>1 <= n <= 10<sup>5</sup></code>
+*   <code>1 <= nums1[i], nums2[i] <= 10<sup>6</sup></code>
+*   `1 <= k <= n`

src/main/kotlin/g3401_3500/s3479_fruits_into_baskets_iii/Solution.kt

@@ -0,0 +1,53 @@
+package g3401_3500.s3479_fruits_into_baskets_iii
+
+// #Medium #Array #Binary_Search #Ordered_Set #Segment_Tree
+// #2025_03_11_Time_53_ms_(92.86%)_Space_86.21_MB_(7.14%)
+
+import kotlin.math.max
+
+class Solution {
+    fun numOfUnplacedFruits(fruits: IntArray, baskets: IntArray): Int {
+        val n = baskets.size
+        var size = 1
+        while (size < n) {
+            size = size shl 1
+        }
+        val seg = IntArray(2 * size)
+        for (i in 0..<n) {
+            seg[size + i] = baskets[i]
+        }
+        for (i in n..<size) {
+            seg[size + i] = 0
+        }
+        for (i in size - 1 downTo 1) {
+            seg[i] = max(seg[i shl 1].toDouble(), seg[i shl 1 or 1].toDouble()).toInt()
+        }
+        var ans = 0
+        for (f in fruits) {
+            if (seg[1] < f) {
+                ans++
+                continue
+            }
+            var idx = 1
+            while (idx < size) {
+                if (seg[idx shl 1] >= f) {
+                    idx = idx shl 1
+                } else {
+                    idx = idx shl 1 or 1
+                }
+            }
+            update(seg, idx - size, 0, size)
+        }
+        return ans
+    }
+
+    private fun update(seg: IntArray, pos: Int, `val`: Int, size: Int) {
+        var i = pos + size
+        seg[i] = `val`
+        i /= 2
+        while (i > 0) {
+            seg[i] = max(seg[i shl 1].toDouble(), seg[i shl 1 or 1].toDouble()).toInt()
+            i /= 2
+        }
+    }
+}

src/main/kotlin/g3401_3500/s3479_fruits_into_baskets_iii/readme.md

@@ -0,0 +1,47 @@
+3479\. Fruits Into Baskets III
+
+Medium
+
+You are given two arrays of integers, `fruits` and `baskets`, each of length `n`, where `fruits[i]` represents the **quantity** of the <code>i<sup>th</sup></code> type of fruit, and `baskets[j]` represents the **capacity** of the <code>j<sup>th</sup></code> basket.
+
+From left to right, place the fruits according to these rules:
+
+*   Each fruit type must be placed in the **leftmost available basket** with a capacity **greater than or equal** to the quantity of that fruit type.
+*   Each basket can hold **only one** type of fruit.
+*   If a fruit type **cannot be placed** in any basket, it remains **unplaced**.
+
+Return the number of fruit types that remain unplaced after all possible allocations are made.
+
+**Example 1:**
+
+**Input:** fruits = [4,2,5], baskets = [3,5,4]
+
+**Output:** 1
+
+**Explanation:**
+
+*   `fruits[0] = 4` is placed in `baskets[1] = 5`.
+*   `fruits[1] = 2` is placed in `baskets[0] = 3`.
+*   `fruits[2] = 5` cannot be placed in `baskets[2] = 4`.
+
+Since one fruit type remains unplaced, we return 1.
+
+**Example 2:**
+
+**Input:** fruits = [3,6,1], baskets = [6,4,7]
+
+**Output:** 0
+
+**Explanation:**
+
+*   `fruits[0] = 3` is placed in `baskets[0] = 6`.
+*   `fruits[1] = 6` cannot be placed in `baskets[1] = 4` (insufficient capacity) but can be placed in the next available basket, `baskets[2] = 7`.
+*   `fruits[2] = 1` is placed in `baskets[1] = 4`.
+
+Since all fruits are successfully placed, we return 0.
+
+**Constraints:**
+
+*   `n == fruits.length == baskets.length`
+*   <code>1 <= n <= 10<sup>5</sup></code>
+*   <code>1 <= fruits[i], baskets[i] <= 10<sup>9</sup></code>

src/main/kotlin/g3401_3500/s3480_maximize_subarrays_after_removing_one_conflicting_pair/Solution.kt

@@ -0,0 +1,86 @@
+package g3401_3500.s3480_maximize_subarrays_after_removing_one_conflicting_pair
+
+// #Hard #Array #Prefix_Sum #Enumeration #Segment_Tree
+// #2025_03_11_Time_48_ms_(100.00%)_Space_164.15_MB_(100.00%)
+
+import kotlin.math.max
+import kotlin.math.min
+
+class Solution {
+    fun maxSubarrays(n: Int, conflictingPairs: Array<IntArray>): Long {
+        val totalSubarrays = n.toLong() * (n + 1) / 2
+        val h = IntArray(n + 1)
+        val d2 = IntArray(n + 1)
+        h.fill(n + 1)
+        d2.fill(n + 1)
+        for (pair in conflictingPairs) {
+            var a = pair[0]
+            var b = pair[1]
+            if (a > b) {
+                val temp = a
+                a = b
+                b = temp
+            }
+            if (b < h[a]) {
+                d2[a] = h[a]
+                h[a] = b
+            } else if (b < d2[a]) {
+                d2[a] = b
+            }
+        }
+        val f = IntArray(n + 2)
+        f[n + 1] = n + 1
+        f[n] = h[n]
+        for (i in n - 1 downTo 1) {
+            f[i] = min(h[i], f[i + 1]).toInt()
+        }
+        // forbiddenCount(x) returns (n - x + 1) if x <= n, else 0.
+        // This is the number of forbidden subarrays starting at some i when f[i] = x.
+        var originalUnion: Long = 0
+        for (i in 1..n) {
+            if (f[i] <= n) {
+                originalUnion += (n - f[i] + 1).toLong()
+            }
+        }
+        val originalValid = totalSubarrays - originalUnion
+        var best = originalValid
+        // For each index j (1 <= j <= n) where a candidate conflicting pair exists,
+        // simulate removal of the pair that gave h[j] (if any).
+        // (If there is no candidate pair at j, h[j] remains n+1.)
+        for (j in 1..n) {
+            // no conflicting pair at index j
+            if (h[j] == n + 1) {
+                continue
+            }
+            // Simulate removal: new candidate at j becomes d2[j]
+            val newCandidate = if (j < n) min(d2[j], f[j + 1]).toInt() else d2[j]
+            // We'll recompute the new f values for indices 1..j.
+            // Let newF[i] denote the updated value.
+            // For i > j, newF[i] remains as original f[i].
+            // For i = j, newF[j] = min( newCandidate, f[j+1] ) (which is newCandidate by
+            // definition).
+            val newFj = newCandidate
+            // forbiddenCount(x) is defined as (n - x + 1) if x<= n, else 0.
+            var delta = forbiddenCount(newFj, n) - forbiddenCount(f[j], n)
+            var cur = newFj
+            // Now update backwards for i = j-1 down to 1.
+            for (i in j - 1 downTo 1) {
+                val newVal = min(h[i], cur)
+                // no further change for i' <= i
+                if (newVal == f[i]) {
+                    break
+                }
+                delta += forbiddenCount(newVal, n) - forbiddenCount(f[i], n)
+                cur = newVal
+            }
+            val newUnion = originalUnion + delta
+            val newValid = totalSubarrays - newUnion
+            best = max(best, newValid)
+        }
+        return best
+    }
+
+    private fun forbiddenCount(x: Int, n: Int): Long {
+        return (if (x <= n) (n - x + 1) else 0).toLong()
+    }
+}

src/main/kotlin/g3401_3500/s3480_maximize_subarrays_after_removing_one_conflicting_pair/readme.md

@@ -0,0 +1,41 @@
+3480\. Maximize Subarrays After Removing One Conflicting Pair
+
+Hard
+
+You are given an integer `n` which represents an array `nums` containing the numbers from 1 to `n` in order. Additionally, you are given a 2D array `conflictingPairs`, where `conflictingPairs[i] = [a, b]` indicates that `a` and `b` form a conflicting pair.
+
+Remove **exactly** one element from `conflictingPairs`. Afterward, count the number of non-empty subarrays of `nums` which do not contain both `a` and `b` for any remaining conflicting pair `[a, b]`.
+
+Return the **maximum** number of subarrays possible after removing **exactly** one conflicting pair.
+
+**Example 1:**
+
+**Input:** n = 4, conflictingPairs = [[2,3],[1,4]]
+
+**Output:** 9
+
+**Explanation:**
+
+*   Remove `[2, 3]` from `conflictingPairs`. Now, `conflictingPairs = [[1, 4]]`.
+*   There are 9 subarrays in `nums` where `[1, 4]` do not appear together. They are `[1]`, `[2]`, `[3]`, `[4]`, `[1, 2]`, `[2, 3]`, `[3, 4]`, `[1, 2, 3]` and `[2, 3, 4]`.
+*   The maximum number of subarrays we can achieve after removing one element from `conflictingPairs` is 9.
+
+**Example 2:**
+
+**Input:** n = 5, conflictingPairs = [[1,2],[2,5],[3,5]]
+
+**Output:** 12
+
+**Explanation:**
+
+*   Remove `[1, 2]` from `conflictingPairs`. Now, `conflictingPairs = [[2, 5], [3, 5]]`.
+*   There are 12 subarrays in `nums` where `[2, 5]` and `[3, 5]` do not appear together.
+*   The maximum number of subarrays we can achieve after removing one element from `conflictingPairs` is 12.
+
+**Constraints:**
+
+*   <code>2 <= n <= 10<sup>5</sup></code>
+*   `1 <= conflictingPairs.length <= 2 * n`
+*   `conflictingPairs[i].length == 2`
+*   `1 <= conflictingPairs[i][j] <= n`
+*   `conflictingPairs[i][0] != conflictingPairs[i][1]`