Improved task 3433

Author: javadev

src/main/kotlin/g3401_3500/s3433_count_mentions_per_user/Solution.kt

@@ -1,50 +1,44 @@
 package g3401_3500.s3433_count_mentions_per_user
 
-// #Medium #Array #Math #Sorting #Simulation #2025_01_26_Time_90_(100.00%)_Space_49.08_(100.00%)
+// #Medium #Array #Math #Sorting #Simulation #2025_01_29_Time_52_(100.00%)_Space_47.22_(60.71%)
 
 class Solution {
     fun countMentions(numberOfUsers: Int, events: List<List<String>>): IntArray {
-        val sortedEvents = events.sortedWith { a, b ->
-            val time1 = a[1].toInt()
-            val time2 = b[1].toInt()
-            if (time1 == time2 && a[0] == "OFFLINE" && b[0] == "MESSAGE") {
-                -1
-            } else {
-                time1 - time2
-            }
-        }
         val ans = IntArray(numberOfUsers)
-        val userTimestamps = IntArray(numberOfUsers)
-        for (event in sortedEvents) {
-            val msg = event[0]
-            val time = event[1].toInt()
-            when (msg) {
-                "OFFLINE" -> {
-                    userTimestamps[event[2].toInt()] = time + 60
+        val l: MutableList<Int?> = ArrayList<Int?>()
+        var c = 0
+        for (i in events.indices) {
+            val s = events[i][0]
+            val ss = events[i][2]
+            if (s == "MESSAGE") {
+                if (ss == "ALL" || ss == "HERE") {
+                    c++
+                    if (ss == "HERE") {
+                        l.add(events[i][1].toInt())
+                    }
+                } else {
+                    val sss: Array<String?> = ss.split(" ".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray()
+                    for (j in sss.indices) {
+                        val jj = sss[j]!!.substring(2, sss[j]!!.length).toInt()
+                        ans[jj]++
+                    }
                 }
-                "MESSAGE" -> {
-                    val mentionsString = event[2]
-                    when (mentionsString) {
-                        "ALL" -> {
-                            for (i in 0 until numberOfUsers) {
-                                ans[i]++
-                            }
-                        }
-                        "HERE" -> {
-                            for (i in 0 until numberOfUsers) {
-                                if (userTimestamps[i] <= time) ans[i]++
-                            }
-                        }
-                        else -> {
-                            mentionsString.split(" ").forEach { id ->
-                                val curr = id.substring(2).toInt()
-                                ans[curr]++
-                            }
-                        }
+            }
+        }
+        for (i in events.indices) {
+            if (events[i][0] == "OFFLINE") {
+                val id = events[i][2].toInt()
+                val a = events[i][1].toInt() + 60
+                for (j in l.indices) {
+                    if (l[j]!! >= a - 60 && l[j]!! < a) {
+                        ans[id]--
                     }
                 }
             }
         }
+        for (i in 0..<numberOfUsers) {
+            ans[i] += c
+        }
         return ans
     }
 }