diff --git a/src/main/kotlin/g1501_1600/s1594_maximum_non_negative_product_in_a_matrix/Solution.kt b/src/main/kotlin/g1501_1600/s1594_maximum_non_negative_product_in_a_matrix/Solution.kt
index a61c55bdb..d1166e8af 100644
--- a/src/main/kotlin/g1501_1600/s1594_maximum_non_negative_product_in_a_matrix/Solution.kt
+++ b/src/main/kotlin/g1501_1600/s1594_maximum_non_negative_product_in_a_matrix/Solution.kt
@@ -6,43 +6,38 @@ package g1501_1600.s1594_maximum_non_negative_product_in_a_matrix
 class Solution {
     private class Tuple(var max: Long, var min: Long)
 
-    fun maxProductPath(grid: Array<IntArray?>?): Int {
+    fun maxProductPath(grid: Array<IntArray>): Int {
         // DP
-        if (grid == null || grid.size == 0 || grid[0] == null || grid[0]!!.size == 0) {
+        if (grid.isEmpty() || grid[0].isEmpty()) {
             return 0
         }
         val rows = grid.size
-        val cols = grid[0]!!.size
-        val dp = Array(rows) { arrayOfNulls<Tuple>(cols) }
-        for (i in 0 until rows) {
-            for (j in 0 until cols) {
-                dp[i][j] = Tuple(1, 1)
-            }
-        }
+        val cols = grid[0].size
+        val dp = Array(rows) { Array(cols) { Tuple(1, 1) } }
         // Init first row and column
-        dp[0][0]!!.max = grid[0]!![0].toLong()
-        dp[0][0]!!.min = grid[0]!![0].toLong()
+        dp[0][0].max = grid[0][0].toLong()
+        dp[0][0].min = grid[0][0].toLong()
         for (i in 1 until rows) {
-            dp[i][0]!!.max = grid[i]!![0] * dp[i - 1][0]!!.max
-            dp[i][0]!!.min = grid[i]!![0] * dp[i - 1][0]!!.min
+            dp[i][0].max = grid[i][0] * dp[i - 1][0].max
+            dp[i][0].min = grid[i][0] * dp[i - 1][0].min
         }
         for (i in 1 until cols) {
-            dp[0][i]!!.max = grid[0]!![i] * dp[0][i - 1]!!.max
-            dp[0][i]!!.min = grid[0]!![i] * dp[0][i - 1]!!.min
+            dp[0][i].max = grid[0][i] * dp[0][i - 1].max
+            dp[0][i].min = grid[0][i] * dp[0][i - 1].min
         }
         // DP
         for (i in 1 until rows) {
             for (j in 1 until cols) {
-                val up1 = dp[i - 1][j]!!.max * grid[i]!![j]
-                val up2 = dp[i - 1][j]!!.min * grid[i]!![j]
-                val left1 = dp[i][j - 1]!!.max * grid[i]!![j]
-                val left2 = dp[i][j - 1]!!.min * grid[i]!![j]
-                dp[i][j]!!.max = Math.max(up1, Math.max(up2, Math.max(left1, left2)))
-                dp[i][j]!!.min = Math.min(up1, Math.min(up2, Math.min(left1, left2)))
+                val up1 = dp[i - 1][j].max * grid[i][j]
+                val up2 = dp[i - 1][j].min * grid[i][j]
+                val left1 = dp[i][j - 1].max * grid[i][j]
+                val left2 = dp[i][j - 1].min * grid[i][j]
+                dp[i][j].max = Math.max(up1, Math.max(up2, Math.max(left1, left2)))
+                dp[i][j].min = Math.min(up1, Math.min(up2, Math.min(left1, left2)))
             }
         }
-        return if (dp[rows - 1][cols - 1]!!.max < 0) {
+        return if (dp[rows - 1][cols - 1].max < 0) {
             -1
-        } else (dp[rows - 1][cols - 1]!!.max % (1e9 + 7)).toInt()
+        } else (dp[rows - 1][cols - 1].max % (1e9 + 7)).toInt()
     }
 }
diff --git a/src/main/kotlin/g1801_1900/s1886_determine_whether_matrix_can_be_obtained_by_rotation/Solution.kt b/src/main/kotlin/g1801_1900/s1886_determine_whether_matrix_can_be_obtained_by_rotation/Solution.kt
index 741145149..ab6c00566 100644
--- a/src/main/kotlin/g1801_1900/s1886_determine_whether_matrix_can_be_obtained_by_rotation/Solution.kt
+++ b/src/main/kotlin/g1801_1900/s1886_determine_whether_matrix_can_be_obtained_by_rotation/Solution.kt
@@ -3,12 +3,10 @@ package g1801_1900.s1886_determine_whether_matrix_can_be_obtained_by_rotation
 // #Easy #Array #Matrix #Programming_Skills_II_Day_7
 // #2023_06_22_Time_147_ms_(85.71%)_Space_34.1_MB_(100.00%)
 
-import java.util.Arrays
-
 class Solution {
-    fun findRotation(mat: Array<IntArray>, target: Array<IntArray?>?): Boolean {
+    fun findRotation(mat: Array<IntArray>, target: Array<IntArray>): Boolean {
         for (i in 0..3) {
-            if (Arrays.deepEquals(mat, target)) {
+            if (mat.contentDeepEquals(target)) {
                 return true
             }
             rotate(mat)
diff --git a/src/main/kotlin/g1901_2000/s1942_the_number_of_the_smallest_unoccupied_chair/Solution.kt b/src/main/kotlin/g1901_2000/s1942_the_number_of_the_smallest_unoccupied_chair/Solution.kt
index bc08a68c5..64e29fd20 100644
--- a/src/main/kotlin/g1901_2000/s1942_the_number_of_the_smallest_unoccupied_chair/Solution.kt
+++ b/src/main/kotlin/g1901_2000/s1942_the_number_of_the_smallest_unoccupied_chair/Solution.kt
@@ -3,7 +3,6 @@ package g1901_2000.s1942_the_number_of_the_smallest_unoccupied_chair
 // #Medium #Array #Heap_Priority_Queue #Ordered_Set
 // #2023_06_20_Time_549_ms_(100.00%)_Space_63.6_MB_(100.00%)
 
-import java.util.Arrays
 import java.util.PriorityQueue
 
 class Solution {
@@ -15,9 +14,8 @@ class Solution {
             all[2 * i] = Person(i, times[i][0], false, true)
             all[2 * i + 1] = Person(i, times[i][1], true, false)
         }
-        Arrays.sort(
-            all
-        ) { a: Person?, b: Person? ->
+
+        all.sortWith { a: Person?, b: Person? ->
             val i = if (a!!.leave) -1 else 1
             val j = if (b!!.leave) -1 else 1
             if (a.time == b.time) i - j else a.time - b.time
diff --git a/src/main/kotlin/g1901_2000/s1985_find_the_kth_largest_integer_in_the_array/Solution.kt b/src/main/kotlin/g1901_2000/s1985_find_the_kth_largest_integer_in_the_array/Solution.kt
index b2608020f..e126b6d31 100644
--- a/src/main/kotlin/g1901_2000/s1985_find_the_kth_largest_integer_in_the_array/Solution.kt
+++ b/src/main/kotlin/g1901_2000/s1985_find_the_kth_largest_integer_in_the_array/Solution.kt
@@ -3,11 +3,9 @@ package g1901_2000.s1985_find_the_kth_largest_integer_in_the_array
 // #Medium #Array #String #Sorting #Heap_Priority_Queue #Divide_and_Conquer #Quickselect
 // #2023_06_21_Time_397_ms_(100.00%)_Space_55.3_MB_(66.67%)
 
-import java.util.Arrays
-
 class Solution {
     fun kthLargestNumber(nums: Array<String>, k: Int): String {
-        Arrays.sort(nums) { n1: String, n2: String -> compareStringInt(n2, n1) }
+        nums.sortWith { n1: String, n2: String -> compareStringInt(n2, n1) }
         return nums[k - 1]
     }
 
@@ -15,7 +13,7 @@ class Solution {
         if (n1.length != n2.length) {
             return if (n1.length < n2.length) -1 else 1
         }
-        for (i in 0 until n1.length) {
+        for (i in n1.indices) {
             val n1Digit = n1[i].code - '0'.code
             val n2Digit = n2[i].code - '0'.code
             if (n1Digit > n2Digit) {
diff --git a/src/main/kotlin/g1901_2000/s1996_the_number_of_weak_characters_in_the_game/Solution.kt b/src/main/kotlin/g1901_2000/s1996_the_number_of_weak_characters_in_the_game/Solution.kt
index 4aabeaf4c..25fe77f68 100644
--- a/src/main/kotlin/g1901_2000/s1996_the_number_of_weak_characters_in_the_game/Solution.kt
+++ b/src/main/kotlin/g1901_2000/s1996_the_number_of_weak_characters_in_the_game/Solution.kt
@@ -3,11 +3,9 @@ package g1901_2000.s1996_the_number_of_weak_characters_in_the_game
 // #Medium #Array #Sorting #Greedy #Stack #Monotonic_Stack
 // #2023_06_21_Time_1234_ms_(100.00%)_Space_98.2_MB_(100.00%)
 
-import java.util.Arrays
-
 class Solution {
     fun numberOfWeakCharacters(properties: Array<IntArray>): Int {
-        Arrays.sort(properties) { a: IntArray, b: IntArray -> if (a[0] == b[0]) b[1] - a[1] else a[0] - b[0] }
+        properties.sortWith { a: IntArray, b: IntArray -> if (a[0] == b[0]) b[1] - a[1] else a[0] - b[0] }
         var max = properties[properties.size - 1][1]
         var count = 0
         for (i in properties.size - 2 downTo 0) {
diff --git a/src/main/kotlin/g2001_2100/s2008_maximum_earnings_from_taxi/Solution.kt b/src/main/kotlin/g2001_2100/s2008_maximum_earnings_from_taxi/Solution.kt
index b4e010f8f..76e34089b 100644
--- a/src/main/kotlin/g2001_2100/s2008_maximum_earnings_from_taxi/Solution.kt
+++ b/src/main/kotlin/g2001_2100/s2008_maximum_earnings_from_taxi/Solution.kt
@@ -3,14 +3,13 @@ package g2001_2100.s2008_maximum_earnings_from_taxi
 // #Medium #Array #Dynamic_Programming #Sorting #Binary_Search
 // #2023_06_23_Time_1008_ms_(100.00%)_Space_67.3_MB_(100.00%)
 
-import java.util.Arrays
 import java.util.PriorityQueue
 
 @Suppress("UNUSED_PARAMETER")
 class Solution {
     fun maxTaxiEarnings(n: Int, rides: Array<IntArray>): Long {
         // Sort based on start time
-        Arrays.sort(rides) { a: IntArray, b: IntArray ->
+        rides.sortWith { a: IntArray, b: IntArray ->
             a[0] - b[0]
         }
         var max: Long = 0
diff --git a/src/main/kotlin/g2001_2100/s2054_two_best_non_overlapping_events/Solution.kt b/src/main/kotlin/g2001_2100/s2054_two_best_non_overlapping_events/Solution.kt
index e6e010498..59681f391 100644
--- a/src/main/kotlin/g2001_2100/s2054_two_best_non_overlapping_events/Solution.kt
+++ b/src/main/kotlin/g2001_2100/s2054_two_best_non_overlapping_events/Solution.kt
@@ -3,11 +3,9 @@ package g2001_2100.s2054_two_best_non_overlapping_events
 // #Medium #Array #Dynamic_Programming #Sorting #Binary_Search #Heap_Priority_Queue
 // #2023_06_25_Time_851_ms_(100.00%)_Space_108.7_MB_(50.00%)
 
-import java.util.Arrays
-
 class Solution {
     fun maxTwoEvents(events: Array<IntArray>): Int {
-        Arrays.sort(events) { a: IntArray, b: IntArray -> a[0] - b[0] }
+        events.sortWith { a: IntArray, b: IntArray -> a[0] - b[0] }
         val max = IntArray(events.size)
         for (i in events.indices.reversed()) {
             if (i == events.size - 1) {
diff --git a/src/main/kotlin/g2001_2100/s2092_find_all_people_with_secret/Solution.kt b/src/main/kotlin/g2001_2100/s2092_find_all_people_with_secret/Solution.kt
index 92c376fc5..e416b5ad4 100644
--- a/src/main/kotlin/g2001_2100/s2092_find_all_people_with_secret/Solution.kt
+++ b/src/main/kotlin/g2001_2100/s2092_find_all_people_with_secret/Solution.kt
@@ -3,12 +3,10 @@ package g2001_2100.s2092_find_all_people_with_secret
 // #Hard #Sorting #Depth_First_Search #Breadth_First_Search #Graph #Union_Find
 // #2023_06_28_Time_1086_ms_(100.00%)_Space_104.2_MB_(100.00%)
 
-import java.util.Arrays
-
 @Suppress("NAME_SHADOWING")
 class Solution {
     fun findAllPeople(n: Int, meetings: Array<IntArray>, firstPerson: Int): List<Int> {
-        Arrays.sort(meetings) { a: IntArray, b: IntArray -> a[2] - b[2] }
+        meetings.sortWith { a: IntArray, b: IntArray -> a[2] - b[2] }
         val uf = UF(n)
         // base
         uf.union(0, firstPerson)
diff --git a/src/main/kotlin/g2101_2200/s2136_earliest_possible_day_of_full_bloom/Solution.kt b/src/main/kotlin/g2101_2200/s2136_earliest_possible_day_of_full_bloom/Solution.kt
index 57a5e0e09..e6cb1647c 100644
--- a/src/main/kotlin/g2101_2200/s2136_earliest_possible_day_of_full_bloom/Solution.kt
+++ b/src/main/kotlin/g2101_2200/s2136_earliest_possible_day_of_full_bloom/Solution.kt
@@ -2,7 +2,6 @@ package g2101_2200.s2136_earliest_possible_day_of_full_bloom
 
 // #Hard #Array #Sorting #Greedy #2023_06_25_Time_968_ms_(100.00%)_Space_57.2_MB_(100.00%)
 
-import java.util.Arrays
 import java.util.Collections
 
 class Solution {
@@ -15,7 +14,7 @@ class Solution {
         for (i in 0 until n) {
             arr[i] = Seed(plantTime[i], growTime[i])
         }
-        Arrays.sort(arr, Collections.reverseOrder())
+        arr.sortWith(Collections.reverseOrder())
         var ans = arr[0]!!.plantTime + arr[0]!!.growTime
         var lastPlantDay = arr[0]!!.plantTime
         for (i in 1 until n) {
diff --git a/src/main/kotlin/g2201_2300/s2250_count_number_of_rectangles_containing_each_point/Solution.kt b/src/main/kotlin/g2201_2300/s2250_count_number_of_rectangles_containing_each_point/Solution.kt
index 705dfc8a1..67d007bcc 100644
--- a/src/main/kotlin/g2201_2300/s2250_count_number_of_rectangles_containing_each_point/Solution.kt
+++ b/src/main/kotlin/g2201_2300/s2250_count_number_of_rectangles_containing_each_point/Solution.kt
@@ -3,8 +3,6 @@ package g2201_2300.s2250_count_number_of_rectangles_containing_each_point
 // #Medium #Array #Sorting #Binary_Search #Binary_Indexed_Tree
 // #2023_06_27_Time_967_ms_(100.00%)_Space_85.4_MB_(100.00%)
 
-import java.util.Arrays
-
 class Solution {
     fun countRectangles(rectangles: Array<IntArray>, points: Array<IntArray>): IntArray {
         val n = rectangles.size
@@ -14,7 +12,7 @@ class Solution {
         for (i in 0 until q) {
             es[n + i] = intArrayOf(points[i][0], points[i][1], i)
         }
-        Arrays.sort(es) { x: IntArray?, y: IntArray? -> if (x!![0] != y!![0]) -(x[0] - y[0]) else x.size - y.size }
+        es.sortWith { x: IntArray?, y: IntArray? -> if (x!![0] != y!![0]) -(x[0] - y[0]) else x.size - y.size }
         val ct = IntArray(101)
         val ans = IntArray(q)
         for (e in es) {
diff --git a/src/main/kotlin/g2201_2300/s2251_number_of_flowers_in_full_bloom/Solution.kt b/src/main/kotlin/g2201_2300/s2251_number_of_flowers_in_full_bloom/Solution.kt
index caffcace1..59d603025 100644
--- a/src/main/kotlin/g2201_2300/s2251_number_of_flowers_in_full_bloom/Solution.kt
+++ b/src/main/kotlin/g2201_2300/s2251_number_of_flowers_in_full_bloom/Solution.kt
@@ -3,21 +3,20 @@ package g2201_2300.s2251_number_of_flowers_in_full_bloom
 // #Hard #Array #Hash_Table #Sorting #Binary_Search #Prefix_Sum #Ordered_Set
 // #2023_06_28_Time_973_ms_(100.00%)_Space_88.6_MB_(100.00%)
 
-import java.util.Arrays
 import java.util.PriorityQueue
 
 class Solution {
     fun fullBloomFlowers(flowers: Array<IntArray>, persons: IntArray): IntArray {
-        Arrays.sort(flowers, { a: IntArray, b: IntArray -> a[0].compareTo(b[0]) })
+        flowers.sortWith { a: IntArray, b: IntArray -> a[0].compareTo(b[0]) }
         val ans = IntArray(persons.size)
-        val pq = PriorityQueue({ a: Pair, b: Pair -> a.j.compareTo(b.j) })
+        val pq = PriorityQueue { a: Pair, b: Pair -> a.j.compareTo(b.j) }
         var j = 0
         val t = Array(persons.size) { IntArray(2) }
         for (i in persons.indices) {
             t[i][0] = persons[i]
             t[i][1] = i
         }
-        Arrays.sort(t, { a: IntArray, b: IntArray -> a[0].compareTo(b[0]) })
+        t.sortWith { a: IntArray, b: IntArray -> a[0].compareTo(b[0]) }
         for (ints in t) {
             while (pq.isNotEmpty()) {
                 if (pq.peek().j < ints[0]) {
diff --git a/src/main/kotlin/g2201_2300/s2271_maximum_white_tiles_covered_by_a_carpet/Solution.kt b/src/main/kotlin/g2201_2300/s2271_maximum_white_tiles_covered_by_a_carpet/Solution.kt
index 20cdcac56..618ebea53 100644
--- a/src/main/kotlin/g2201_2300/s2271_maximum_white_tiles_covered_by_a_carpet/Solution.kt
+++ b/src/main/kotlin/g2201_2300/s2271_maximum_white_tiles_covered_by_a_carpet/Solution.kt
@@ -3,11 +3,9 @@ package g2201_2300.s2271_maximum_white_tiles_covered_by_a_carpet
 // #Medium #Array #Sorting #Greedy #Binary_Search #Prefix_Sum
 // #2023_06_28_Time_692_ms_(100.00%)_Space_66.2_MB_(100.00%)
 
-import java.util.Arrays
-
 class Solution {
     fun maximumWhiteTiles(tiles: Array<IntArray>, carpetLength: Int): Int {
-        Arrays.sort(tiles, { x: IntArray, y: IntArray -> x[0].compareTo(y[0]) })
+        tiles.sortWith { x: IntArray, y: IntArray -> x[0].compareTo(y[0]) }
         var currentCover = Math.min(tiles[0][1] - tiles[0][0] + 1, carpetLength)
         var maxCover = currentCover
         var head = 1
diff --git a/src/main/kotlin/g2201_2300/s2280_minimum_lines_to_represent_a_line_chart/Solution.kt b/src/main/kotlin/g2201_2300/s2280_minimum_lines_to_represent_a_line_chart/Solution.kt
index cb719a6e4..a8d21b20b 100644
--- a/src/main/kotlin/g2201_2300/s2280_minimum_lines_to_represent_a_line_chart/Solution.kt
+++ b/src/main/kotlin/g2201_2300/s2280_minimum_lines_to_represent_a_line_chart/Solution.kt
@@ -3,14 +3,12 @@ package g2201_2300.s2280_minimum_lines_to_represent_a_line_chart
 // #Medium #Array #Math #Sorting #Geometry #Number_Theory
 // #2023_06_28_Time_765_ms_(100.00%)_Space_98.8_MB_(100.00%)
 
-import java.util.Arrays
-
 class Solution {
     fun minimumLines(stockPrices: Array<IntArray>): Int {
         if (stockPrices.size == 1) {
             return 0
         }
-        Arrays.sort(stockPrices) { a: IntArray, b: IntArray -> a[0] - b[0] }
+        stockPrices.sortWith { a: IntArray, b: IntArray -> a[0] - b[0] }
         // multiply with 1.0 to make it double and multiply with 100 for making it big so that
         // difference won't come out to be very less and after division it become 0.
         // failing for one of the case without multiply 100
diff --git a/src/main/kotlin/g2401_2500/s2402_meeting_rooms_iii/Solution.kt b/src/main/kotlin/g2401_2500/s2402_meeting_rooms_iii/Solution.kt
index 39b7857f0..2b8ea4626 100644
--- a/src/main/kotlin/g2401_2500/s2402_meeting_rooms_iii/Solution.kt
+++ b/src/main/kotlin/g2401_2500/s2402_meeting_rooms_iii/Solution.kt
@@ -3,13 +3,11 @@ package g2401_2500.s2402_meeting_rooms_iii
 // #Hard #Array #Sorting #Heap_Priority_Queue
 // #2023_07_03_Time_976_ms_(100.00%)_Space_108.7_MB_(66.67%)
 
-import java.util.Arrays
-
 class Solution {
     fun mostBooked(n: Int, meetings: Array<IntArray>): Int {
         val counts = IntArray(n)
         val endTimes = LongArray(n)
-        Arrays.sort(meetings) { a: IntArray, b: IntArray -> Integer.compare(a[0], b[0]) }
+        meetings.sortWith { a: IntArray, b: IntArray -> Integer.compare(a[0], b[0]) }
         for (meeting in meetings) {
             val id = findRoomId(endTimes, meeting[0])
             counts[id]++
diff --git a/src/main/kotlin/g2401_2500/s2463_minimum_total_distance_traveled/Solution.kt b/src/main/kotlin/g2401_2500/s2463_minimum_total_distance_traveled/Solution.kt
index ea1d8e1c7..c93031e70 100644
--- a/src/main/kotlin/g2401_2500/s2463_minimum_total_distance_traveled/Solution.kt
+++ b/src/main/kotlin/g2401_2500/s2463_minimum_total_distance_traveled/Solution.kt
@@ -3,14 +3,12 @@ package g2401_2500.s2463_minimum_total_distance_traveled
 // #Hard #Array #Dynamic_Programming #Sorting
 // #2023_07_05_Time_153_ms_(100.00%)_Space_37_MB_(100.00%)
 
-import java.util.Arrays
-
 class Solution {
     fun minimumTotalDistance(robot: List<Int>, f: Array<IntArray>): Long {
         // sort factories :
         // 1. move all factories with 0-capacity to the end
         // 2. sort everything else by x-position in asc order
-        Arrays.sort(f) { a: IntArray, b: IntArray -> if (a[1] == 0) 1 else if (b[1] == 0) -1 else a[0] - b[0] }
+        f.sortWith { a: IntArray, b: IntArray -> if (a[1] == 0) 1 else if (b[1] == 0) -1 else a[0] - b[0] }
         // Sort robots by x-position in asc order
         // As we don't know the implementation of the List that is passed, it is better to map it to
         // an array explicitly
diff --git a/src/main/kotlin/g2501_2600/s2503_maximum_number_of_points_from_grid_queries/Solution.kt b/src/main/kotlin/g2501_2600/s2503_maximum_number_of_points_from_grid_queries/Solution.kt
index 27c5f7eba..63d13c90e 100644
--- a/src/main/kotlin/g2501_2600/s2503_maximum_number_of_points_from_grid_queries/Solution.kt
+++ b/src/main/kotlin/g2501_2600/s2503_maximum_number_of_points_from_grid_queries/Solution.kt
@@ -4,7 +4,6 @@ package g2501_2600.s2503_maximum_number_of_points_from_grid_queries
 // #2023_07_04_Time_581_ms_(100.00%)_Space_62.6_MB_(100.00%)
 
 import java.util.ArrayDeque
-import java.util.Arrays
 import java.util.PriorityQueue
 import java.util.Queue
 
@@ -19,9 +18,9 @@ class Solution {
         for (i in queries.indices) {
             index[i] = i
         }
-        Arrays.sort(index, { o: Int?, m: Int? -> queries[o!!].compareTo(queries[m!!]) })
+        index.sortWith { o: Int?, m: Int? -> queries[o!!].compareTo(queries[m!!]) }
         val q1: Queue<IntArray> = ArrayDeque()
-        val q2 = PriorityQueue({ a: IntArray, b: IntArray -> a[2].compareTo(b[2]) })
+        val q2 = PriorityQueue { a: IntArray, b: IntArray -> a[2].compareTo(b[2]) }
         q2.offer(intArrayOf(0, 0, grid[0][0]))
         val visited = Array(r) { BooleanArray(c) }
         var count = 0
diff --git a/src/main/kotlin/g2501_2600/s2542_maximum_subsequence_score/Solution.kt b/src/main/kotlin/g2501_2600/s2542_maximum_subsequence_score/Solution.kt
index 6733fc65b..3b59b073b 100644
--- a/src/main/kotlin/g2501_2600/s2542_maximum_subsequence_score/Solution.kt
+++ b/src/main/kotlin/g2501_2600/s2542_maximum_subsequence_score/Solution.kt
@@ -3,7 +3,6 @@ package g2501_2600.s2542_maximum_subsequence_score
 // #Medium #Array #Sorting #Greedy #Heap_Priority_Queue
 // #2023_07_04_Time_780_ms_(81.97%)_Space_56.7_MB_(99.45%)
 
-import java.util.Arrays
 import java.util.PriorityQueue
 
 class Solution {
@@ -15,9 +14,8 @@ class Solution {
         for (i in 0 until n) {
             nums[i] = PairInfo(nums1[i], nums2[i])
         }
-        Arrays.sort(
-            nums
-        ) { a: PairInfo?, b: PairInfo? ->
+
+        nums.sortWith sort@{ a: PairInfo?, b: PairInfo? ->
             if (a!!.val2 == b!!.val2) {
                 return@sort a.val1 - b.val1
             }
diff --git a/src/main/kotlin/g2501_2600/s2545_sort_the_students_by_their_kth_score/Solution.kt b/src/main/kotlin/g2501_2600/s2545_sort_the_students_by_their_kth_score/Solution.kt
index 707a52048..52b04d89f 100644
--- a/src/main/kotlin/g2501_2600/s2545_sort_the_students_by_their_kth_score/Solution.kt
+++ b/src/main/kotlin/g2501_2600/s2545_sort_the_students_by_their_kth_score/Solution.kt
@@ -2,11 +2,9 @@ package g2501_2600.s2545_sort_the_students_by_their_kth_score
 
 // #Medium #Array #Sorting #Matrix #2023_07_04_Time_442_ms_(100.00%)_Space_53.3_MB_(100.00%)
 
-import java.util.Arrays
-
 class Solution {
     fun sortTheStudents(score: Array<IntArray>, k: Int): Array<IntArray> {
-        Arrays.sort(score) { o1: IntArray, o2: IntArray -> o2[k] - o1[k] }
+        score.sortWith { o1: IntArray, o2: IntArray -> o2[k] - o1[k] }
         return score
     }
 }
diff --git a/src/main/kotlin/g2501_2600/s2580_count_ways_to_group_overlapping_ranges/Solution.kt b/src/main/kotlin/g2501_2600/s2580_count_ways_to_group_overlapping_ranges/Solution.kt
index 81d192e87..7d5c45fb7 100644
--- a/src/main/kotlin/g2501_2600/s2580_count_ways_to_group_overlapping_ranges/Solution.kt
+++ b/src/main/kotlin/g2501_2600/s2580_count_ways_to_group_overlapping_ranges/Solution.kt
@@ -2,13 +2,11 @@ package g2501_2600.s2580_count_ways_to_group_overlapping_ranges
 
 // #Medium #Array #Sorting #2023_07_10_Time_669_ms_(100.00%)_Space_122.8_MB_(50.00%)
 
-import java.util.Arrays
-
 @Suppress("NAME_SHADOWING")
 class Solution {
     fun countWays(ranges: Array<IntArray>): Int {
         var cnt = 1
-        Arrays.sort(ranges) { a, b -> if (a[0] != b[0]) a[0] - b[0] else a[1] - b[1] }
+        ranges.sortWith { a, b -> if (a[0] != b[0]) a[0] - b[0] else a[1] - b[1] }
         var curr = ranges[0]
         for (i in 1 until ranges.size) {
             if (ranges[i][1] < curr[0] || ranges[i][0] > curr[1]) {
diff --git a/src/main/kotlin/g2501_2600/s2589_minimum_time_to_complete_all_tasks/Solution.kt b/src/main/kotlin/g2501_2600/s2589_minimum_time_to_complete_all_tasks/Solution.kt
index 54e7a9a55..e693795b8 100644
--- a/src/main/kotlin/g2501_2600/s2589_minimum_time_to_complete_all_tasks/Solution.kt
+++ b/src/main/kotlin/g2501_2600/s2589_minimum_time_to_complete_all_tasks/Solution.kt
@@ -3,13 +3,11 @@ package g2501_2600.s2589_minimum_time_to_complete_all_tasks
 // #Hard #Array #Sorting #Greedy #Binary_Search #Stack
 // #2023_07_12_Time_422_ms_(100.00%)_Space_58.7_MB_(50.00%)
 
-import java.util.Arrays
-
 class Solution {
     fun findMinimumTime(tasks: Array<IntArray>): Int {
         var res = 0
         val arr = BooleanArray(2001)
-        Arrays.sort(tasks) { a: IntArray, b: IntArray ->
+        tasks.sortWith { a: IntArray, b: IntArray ->
             a[1] - b[1]
         }
         for (task in tasks) {
diff --git a/src/main/kotlin/g2701_2800/s2719_count_of_integers/Solution.kt b/src/main/kotlin/g2701_2800/s2719_count_of_integers/Solution.kt
index 4433cc681..8d8e39a3a 100644
--- a/src/main/kotlin/g2701_2800/s2719_count_of_integers/Solution.kt
+++ b/src/main/kotlin/g2701_2800/s2719_count_of_integers/Solution.kt
@@ -2,8 +2,6 @@ package g2701_2800.s2719_count_of_integers
 
 // #Hard #String #Dynamic_Programming #Math #2023_08_02_Time_208_ms_(100.00%)_Space_38_MB_(68.42%)
 
-import java.util.Arrays
-
 class Solution {
     private lateinit var dp: Array<Array<Array<IntArray>>>
     private fun countStrings(i: Int, tight1: Boolean, tight2: Boolean, sum: Int, num1: String, num2: String): Int {
@@ -41,7 +39,7 @@ class Solution {
         for (dim1 in dp) {
             for (dim2 in dim1) {
                 for (dim3 in dim2) {
-                    Arrays.fill(dim3, -1)
+                    dim3.fill(-1)
                 }
             }
         }
diff --git a/src/main/kotlin/g2701_2800/s2747_count_zero_request_servers/Solution.kt b/src/main/kotlin/g2701_2800/s2747_count_zero_request_servers/Solution.kt
index 9a0d2cd37..5eae529d6 100644
--- a/src/main/kotlin/g2701_2800/s2747_count_zero_request_servers/Solution.kt
+++ b/src/main/kotlin/g2701_2800/s2747_count_zero_request_servers/Solution.kt
@@ -3,17 +3,15 @@ package g2701_2800.s2747_count_zero_request_servers
 // #Medium #Array #Hash_Table #Sorting #Sliding_Window
 // #2023_08_08_Time_991_ms_(100.00%)_Space_109.2_MB_(90.00%)
 
-import java.util.Arrays
-
 class Solution {
     fun countServers(n: Int, logs: Array<IntArray>, x: Int, qs: IntArray): IntArray {
         val m = qs.size
         val valIdx = Array(m) { IntArray(2) }
         for (i in 0 until m) valIdx[i] = intArrayOf(qs[i], i)
-        Arrays.sort(valIdx) { a: IntArray, b: IntArray ->
+        valIdx.sortWith { a: IntArray, b: IntArray ->
             a[0] - b[0]
         }
-        Arrays.sort(logs) { a: IntArray, b: IntArray ->
+        logs.sortWith { a: IntArray, b: IntArray ->
             a[1] - b[1]
         }
         var l = 0
diff --git a/src/main/kotlin/g3001_3100/s3068_find_the_maximum_sum_of_node_values/Solution.kt b/src/main/kotlin/g3001_3100/s3068_find_the_maximum_sum_of_node_values/Solution.kt
index ba77a7a5a..b04ba6b30 100644
--- a/src/main/kotlin/g3001_3100/s3068_find_the_maximum_sum_of_node_values/Solution.kt
+++ b/src/main/kotlin/g3001_3100/s3068_find_the_maximum_sum_of_node_values/Solution.kt
@@ -9,7 +9,7 @@ import kotlin.math.min
 
 @Suppress("UNUSED_PARAMETER")
 class Solution {
-    fun maximumValueSum(nums: IntArray, k: Int, edges: Array<IntArray?>?): Long {
+    fun maximumValueSum(nums: IntArray, k: Int, edges: Array<IntArray>): Long {
         var res: Long = 0
         var d = 1 shl 30
         var c = 0