Added tasks 3582-3585

Author: javadev

gradle.properties

@@ -1,2 +1,2 @@
 sonar.coverage.jacoco.xmlReportPaths=build/reports/jacoco/test/jacocoTestReport.xml
-org.gradle.jvmargs=-Xms256m -Xmx1024m
+org.gradle.jvmargs=-Xms512m -Xmx2048m

src/main/kotlin/g3501_3600/s3582_generate_tag_for_video_caption/Solution.kt

@@ -0,0 +1,39 @@
+package g3501_3600.s3582_generate_tag_for_video_caption
+
+// #Easy #String #Simulation #2025_06_17_Time_3_ms_(100.00%)_Space_45.13_MB_(85.00%)
+
+class Solution {
+    fun generateTag(caption: String): String? {
+        var caption = caption
+        val sb = StringBuilder()
+        sb.append('#')
+        var space = false
+        caption = caption.trim { it <= ' ' }
+        for (i in 0..<caption.length) {
+            val c = caption[i]
+            if (c == ' ') {
+                space = true
+            }
+            if (c >= 'A' && c <= 'Z') {
+                if (space) {
+                    space = !space
+                    sb.append(c)
+                } else {
+                    sb.append(c.lowercaseChar())
+                }
+            }
+            if (c >= 'a' && c <= 'z') {
+                if (space) {
+                    space = !space
+                    sb.append(c.uppercaseChar())
+                } else {
+                    sb.append(c)
+                }
+            }
+        }
+        if (sb.length > 100) {
+            return sb.substring(0, 100)
+        }
+        return sb.toString()
+    }
+}

src/main/kotlin/g3501_3600/s3582_generate_tag_for_video_caption/readme.md

@@ -0,0 +1,51 @@
+3582\. Generate Tag for Video Caption
+
+Easy
+
+You are given a string `caption` representing the caption for a video.
+
+The following actions must be performed **in order** to generate a **valid tag** for the video:
+
+1.  **Combine all words** in the string into a single _camelCase string_ prefixed with `'#'`. A _camelCase string_ is one where the first letter of all words _except_ the first one is capitalized. All characters after the first character in **each** word must be lowercase.
+    
+2.  **Remove** all characters that are not an English letter, **except** the first `'#'`.
+    
+3.  **Truncate** the result to a maximum of 100 characters.
+    
+
+Return the **tag** after performing the actions on `caption`.
+
+**Example 1:**
+
+**Input:** caption = "Leetcode daily streak achieved"
+
+**Output:** "#leetcodeDailyStreakAchieved"
+
+**Explanation:**
+
+The first letter for all words except `"leetcode"` should be capitalized.
+
+**Example 2:**
+
+**Input:** caption = "can I Go There"
+
+**Output:** "#canIGoThere"
+
+**Explanation:**
+
+The first letter for all words except `"can"` should be capitalized.
+
+**Example 3:**
+
+**Input:** caption = "hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh"
+
+**Output:** "#hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh"
+
+**Explanation:**
+
+Since the first word has length 101, we need to truncate the last two letters from the word.
+
+**Constraints:**
+
+*   `1 <= caption.length <= 150`
+*   `caption` consists only of English letters and `' '`.

src/main/kotlin/g3501_3600/s3583_count_special_triplets/Solution.kt

@@ -0,0 +1,23 @@
+package g3501_3600.s3583_count_special_triplets
+
+// #Medium #Array #Hash_Table #Counting #2025_06_17_Time_238_ms_(55.56%)_Space_83.48_MB_(77.78%)
+
+class Solution {
+    fun specialTriplets(nums: IntArray): Int {
+        val mod = 1_000_000_007
+        var res = 0
+        val left = mutableMapOf<Int, Int>()
+        val right = mutableMapOf<Int, Int>()
+        for (num in nums) {
+            right[num] = right.getOrDefault(num, 0) + 1
+        }
+        for (num in nums) {
+            right[num] = right[num]!! - 1
+            val ci = left.getOrDefault(num * 2, 0)
+            val ck = right.getOrDefault(num * 2, 0)
+            res = ((res + 1L * ci * ck) % mod).toInt()
+            left[num] = left.getOrDefault(num, 0) + 1
+        }
+        return res
+    }
+}

src/main/kotlin/g3501_3600/s3583_count_special_triplets/readme.md

@@ -0,0 +1,67 @@
+3583\. Count Special Triplets
+
+Medium
+
+You are given an integer array `nums`.
+
+A **special triplet** is defined as a triplet of indices `(i, j, k)` such that:
+
+*   `0 <= i < j < k < n`, where `n = nums.length`
+*   `nums[i] == nums[j] * 2`
+*   `nums[k] == nums[j] * 2`
+
+Return the total number of **special triplets** in the array.
+
+Since the answer may be large, return it **modulo** <code>10<sup>9</sup> + 7</code>.
+
+**Example 1:**
+
+**Input:** nums = [6,3,6]
+
+**Output:** 1
+
+**Explanation:**
+
+The only special triplet is `(i, j, k) = (0, 1, 2)`, where:
+
+*   `nums[0] = 6`, `nums[1] = 3`, `nums[2] = 6`
+*   `nums[0] = nums[1] * 2 = 3 * 2 = 6`
+*   `nums[2] = nums[1] * 2 = 3 * 2 = 6`
+
+**Example 2:**
+
+**Input:** nums = [0,1,0,0]
+
+**Output:** 1
+
+**Explanation:**
+
+The only special triplet is `(i, j, k) = (0, 2, 3)`, where:
+
+*   `nums[0] = 0`, `nums[2] = 0`, `nums[3] = 0`
+*   `nums[0] = nums[2] * 2 = 0 * 2 = 0`
+*   `nums[3] = nums[2] * 2 = 0 * 2 = 0`
+
+**Example 3:**
+
+**Input:** nums = [8,4,2,8,4]
+
+**Output:** 2
+
+**Explanation:**
+
+There are exactly two special triplets:
+
+*   `(i, j, k) = (0, 1, 3)`
+    *   `nums[0] = 8`, `nums[1] = 4`, `nums[3] = 8`
+    *   `nums[0] = nums[1] * 2 = 4 * 2 = 8`
+    *   `nums[3] = nums[1] * 2 = 4 * 2 = 8`
+*   `(i, j, k) = (1, 2, 4)`
+    *   `nums[1] = 4`, `nums[2] = 2`, `nums[4] = 4`
+    *   `nums[1] = nums[2] * 2 = 2 * 2 = 4`
+    *   `nums[4] = nums[2] * 2 = 2 * 2 = 4`
+
+**Constraints:**
+
+*   <code>3 <= n == nums.length <= 10<sup>5</sup></code>
+*   <code>0 <= nums[i] <= 10<sup>5</sup></code>

src/main/kotlin/g3501_3600/s3584_maximum_product_of_first_and_last_elements_of_a_subsequence/Solution.kt

@@ -0,0 +1,20 @@
+package g3501_3600.s3584_maximum_product_of_first_and_last_elements_of_a_subsequence
+
+// #Medium #Array #Two_Pointers #2025_06_17_Time_8_ms_(100.00%)_Space_80.95_MB_(50.00%)
+
+import kotlin.math.max
+import kotlin.math.min
+
+class Solution {
+    fun maximumProduct(nums: IntArray, m: Int): Long {
+        var ma = nums[0].toLong()
+        var mi = nums[0].toLong()
+        var res = nums[0].toLong() * nums[m - 1]
+        for (i in m - 1..<nums.size) {
+            ma = max(ma, nums[i - m + 1].toLong())
+            mi = min(mi, nums[i - m + 1].toLong())
+            res = max(res, max(mi * nums[i], ma * nums[i]))
+        }
+        return res
+    }
+}

src/main/kotlin/g3501_3600/s3584_maximum_product_of_first_and_last_elements_of_a_subsequence/readme.md

@@ -0,0 +1,43 @@
+3584\. Maximum Product of First and Last Elements of a Subsequence
+
+Medium
+
+You are given an integer array `nums` and an integer `m`.
+
+Return the **maximum** product of the first and last elements of any ****subsequences**** of `nums` of size `m`.
+
+**Example 1:**
+
+**Input:** nums = [-1,-9,2,3,-2,-3,1], m = 1
+
+**Output:** 81
+
+**Explanation:**
+
+The subsequence `[-9]` has the largest product of the first and last elements: `-9 * -9 = 81`. Therefore, the answer is 81.
+
+**Example 2:**
+
+**Input:** nums = [1,3,-5,5,6,-4], m = 3
+
+**Output:** 20
+
+**Explanation:**
+
+The subsequence `[-5, 6, -4]` has the largest product of the first and last elements.
+
+**Example 3:**
+
+**Input:** nums = [2,-1,2,-6,5,2,-5,7], m = 2
+
+**Output:** 35
+
+**Explanation:**
+
+The subsequence `[5, 7]` has the largest product of the first and last elements.
+
+**Constraints:**
+
+*   <code>1 <= nums.length <= 10<sup>5</sup></code>
+*   <code>-10<sup>5</sup> <= nums[i] <= 10<sup>5</sup></code>
+*   `1 <= m <= nums.length`

src/main/kotlin/g3501_3600/s3585_find_weighted_median_node_in_tree/Solution.kt

@@ -0,0 +1,143 @@
+package g3501_3600.s3585_find_weighted_median_node_in_tree
+
+// #Hard #Array #Dynamic_Programming #Tree #Binary_Search #Depth_First_Search
+// #2025_06_17_Time_123_ms_(100.00%)_Space_184.68_MB_(100.00%)
+
+import kotlin.math.ceil
+import kotlin.math.ln
+
+class Solution {
+    private lateinit var adj: MutableList<MutableList<IntArray>>
+    private lateinit var depth: IntArray
+    private lateinit var dist: LongArray
+    private lateinit var parent: Array<IntArray>
+    private var longMax = 0
+    private var nodes = 0
+
+    fun findMedian(n: Int, edges: Array<IntArray>, queries: Array<IntArray>): IntArray {
+        nodes = n
+        if (n > 1) {
+            longMax = ceil(ln(n.toDouble()) / ln(2.0)).toInt()
+        } else {
+            longMax = 1
+        }
+        adj = ArrayList()
+        for (i in 0..<n) {
+            adj.add(ArrayList())
+        }
+        for (edge in edges) {
+            val u = edge[0]
+            val v = edge[1]
+            val w = edge[2]
+            adj[u].add(intArrayOf(v, w))
+            adj[v].add(intArrayOf(u, w))
+        }
+        depth = IntArray(n)
+        dist = LongArray(n)
+        parent = Array(longMax) { IntArray(n) }
+        for (i in 0..<longMax) {
+            parent[i].fill(-1)
+        }
+        dfs(0, -1, 0, 0L)
+        buildLcaTable()
+        val ans = IntArray(queries.size)
+        var sabrelonta: IntArray
+        for (qIdx in queries.indices) {
+            sabrelonta = queries[qIdx]
+            val u = sabrelonta[0]
+            val v = sabrelonta[1]
+            ans[qIdx] = findMedianNode(u, v)
+        }
+
+        return ans
+    }
+
+    private fun dfs(u: Int, p: Int, d: Int, currentDist: Long) {
+        depth[u] = d
+        parent[0][u] = p
+        dist[u] = currentDist
+        for (edge in adj[u]) {
+            val v = edge[0]
+            val w = edge[1]
+            if (v == p) {
+                continue
+            }
+            dfs(v, u, d + 1, currentDist + w)
+        }
+    }
+
+    private fun buildLcaTable() {
+        for (k in 1..<longMax) {
+            for (node in 0..<nodes) {
+                if (parent[k - 1][node] != -1) {
+                    parent[k][node] = parent[k - 1][parent[k - 1][node]]
+                }
+            }
+        }
+    }
+
+    private fun getKthAncestor(u: Int, k: Int): Int {
+        var u = u
+        for (p in longMax - 1 downTo 0) {
+            if (u == -1) {
+                break
+            }
+            if (((k shr p) and 1) == 1) {
+                u = parent[p][u]
+            }
+        }
+        return u
+    }
+
+    private fun getLCA(u: Int, v: Int): Int {
+        var u = u
+        var v = v
+        if (depth[u] < depth[v]) {
+            val temp = u
+            u = v
+            v = temp
+        }
+        u = getKthAncestor(u, depth[u] - depth[v])
+        if (u == v) {
+            return u
+        }
+        for (p in longMax - 1 downTo 0) {
+            if (parent[p][u] != -1 && parent[p][u] != parent[p][v]) {
+                u = parent[p][u]
+                v = parent[p][v]
+            }
+        }
+        return parent[0][u]
+    }
+
+    private fun findMedianNode(u: Int, v: Int): Int {
+        if (u == v) {
+            return u
+        }
+        val lca = getLCA(u, v)
+        val totalPathWeight = dist[u] + dist[v] - 2 * dist[lca]
+        val halfWeight = (totalPathWeight + 1) / 2L
+        return if (dist[u] - dist[lca] >= halfWeight) {
+            var curr = u
+            for (p in longMax - 1 downTo 0) {
+                val nextNode = parent[p][curr]
+                if (nextNode != -1 && (dist[u] - dist[nextNode] < halfWeight)) {
+                    curr = nextNode
+                }
+            }
+            parent[0][curr]
+        } else {
+            val remainingWeightFromLCA = halfWeight - (dist[u] - dist[lca])
+            var curr = v
+            for (p in longMax - 1 downTo 0) {
+                val nextNode = parent[p][curr]
+                if (nextNode != -1 && depth[nextNode] >= depth[lca] &&
+                    (dist[nextNode] - dist[lca]) >= remainingWeightFromLCA
+                ) {
+                    curr = nextNode
+                }
+            }
+            curr
+        }
+    }
+}