Improved task 56

Author: javadev

README.md

@@ -546,7 +546,7 @@ implementation 'com.github.javadev:leetcode-in-kotlin:1.9'
 | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
 |-|-|-|-|-|-
 | 0057 |[Insert Interval](src.save/main/kotlin/g0001_0100/s0057_insert_interval/Solution.kt)| Medium | Array | 257 | 99.52
-| 0056 |[Merge Intervals](src.save/main/kotlin/g0001_0100/s0056_merge_intervals/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting | 323 | 99.68
+| 0056 |[Merge Intervals](src.save/main/kotlin/g0001_0100/s0056_merge_intervals/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting | 320 | 94.22
 
 #### Day 18 Stack
 
@@ -661,7 +661,7 @@ implementation 'com.github.javadev:leetcode-in-kotlin:1.9'
 | 0054 |[Spiral Matrix](src.save/main/kotlin/g0001_0100/s0054_spiral_matrix/Solution.kt)| Medium | Top_Interview_Questions, Array, Matrix, Simulation | 224 | 62.50
 | 0048 |[Rotate Image](src.save/main/kotlin/g0001_0100/s0048_rotate_image/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Math, Matrix | 287 | 46.50
 | 0073 |[Set Matrix Zeroes](src.save/main/kotlin/g0001_0100/s0073_set_matrix_zeroes/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table, Matrix | 255 | 100.00
-| 0056 |[Merge Intervals](src.save/main/kotlin/g0001_0100/s0056_merge_intervals/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting | 323 | 99.68
+| 0056 |[Merge Intervals](src.save/main/kotlin/g0001_0100/s0056_merge_intervals/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting | 320 | 94.22
 
 #### Udemy Linked List
 
@@ -889,7 +889,7 @@ implementation 'com.github.javadev:leetcode-in-kotlin:1.9'
 | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
 |-|-|-|-|-|-
 | 0075 |[Sort Colors](src.save/main/kotlin/g0001_0100/s0075_sort_colors/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Two_Pointers | 198 | 85.66
-| 0056 |[Merge Intervals](src.save/main/kotlin/g0001_0100/s0056_merge_intervals/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting | 323 | 99.68
+| 0056 |[Merge Intervals](src.save/main/kotlin/g0001_0100/s0056_merge_intervals/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting | 320 | 94.22
 | 0706 |[Design HashMap](src/main/kotlin/g0701_0800/s0706_design_hashmap/MyHashMap.kt)| Easy | Array, Hash_Table, Design, Linked_List, Hash_Function | 405 | 92.11
 
 #### Day 3 Array
@@ -2209,7 +2209,7 @@ implementation 'com.github.javadev:leetcode-in-kotlin:1.9'
 | 0059 |[Spiral Matrix II](src.save/main/kotlin/g0001_0100/s0059_spiral_matrix_ii/Solution.kt)| Medium | Array, Matrix, Simulation, Data_Structure_II_Day_3_Array | 153 | 100.00
 | 0058 |[Length of Last Word](src.save/main/kotlin/g0001_0100/s0058_length_of_last_word/Solution.kt)| Easy | String, Programming_Skills_II_Day_6, Udemy_Arrays | 243 | 63.33
 | 0057 |[Insert Interval](src.save/main/kotlin/g0001_0100/s0057_insert_interval/Solution.kt)| Medium | Array, Level_2_Day_17_Interval | 257 | 99.52
-| 0056 |[Merge Intervals](src.save/main/kotlin/g0001_0100/s0056_merge_intervals/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Data_Structure_II_Day_2_Array, Level_2_Day_17_Interval, Udemy_2D_Arrays/Matrix | 323 | 99.68
+| 0056 |[Merge Intervals](src.save/main/kotlin/g0001_0100/s0056_merge_intervals/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Sorting, Data_Structure_II_Day_2_Array, Level_2_Day_17_Interval, Udemy_2D_Arrays/Matrix | 320 | 94.22
 | 0055 |[Jump Game](src.save/main/kotlin/g0001_0100/s0055_jump_game/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Greedy, Algorithm_II_Day_12_Dynamic_Programming, Dynamic_Programming_I_Day_4, Udemy_Arrays | 670 | 66.67
 | 0054 |[Spiral Matrix](src.save/main/kotlin/g0001_0100/s0054_spiral_matrix/Solution.kt)| Medium | Top_Interview_Questions, Array, Matrix, Simulation, Programming_Skills_II_Day_8, Level_2_Day_1_Implementation/Simulation, Udemy_2D_Arrays/Matrix | 224 | 62.50
 | 0053 |[Maximum Subarray](src.save/main/kotlin/g0001_0100/s0053_maximum_subarray/Solution.kt)| Easy | Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Divide_and_Conquer, Data_Structure_I_Day_1_Array, Dynamic_Programming_I_Day_5, Udemy_Famous_Algorithm | 662 | 82.48

src.save/main/kotlin/g0001_0100/s0056_merge_intervals/Solution.kt

@@ -2,27 +2,27 @@ package g0001_0100.s0056_merge_intervals
 
 // #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Sorting
 // #Data_Structure_II_Day_2_Array #Level_2_Day_17_Interval #Udemy_2D_Arrays/Matrix
-// #2022_08_29_Time_323_ms_(99.68%)_Space_43_MB_(99.04%)
+// #2023_02_27_Time_320_ms_(94.22%)_Space_44.4_MB_(72.95%)
 
 class Solution {
     fun merge(intervals: Array<IntArray>): Array<IntArray> {
-        intervals.sortWith { a: IntArray, b: IntArray ->
-            Integer.compare(
-                a[0],
-                b[0]
-            )
-        }
-        val list: MutableList<IntArray> = ArrayList()
-        var current = intervals[0]
-        list.add(current)
-        for (next in intervals) {
-            if (current[1] >= next[0]) {
-                current[1] = Math.max(current[1], next[1])
-            } else {
-                current = next
-                list.add(current)
+        val result: MutableList<IntArray> = mutableListOf()
+        if (intervals.size <= 1) return intervals
+        intervals.sortBy { it.first() }
+        var currentRange = 1
+        var begin = intervals[0][0]
+        var end = intervals[0][1]
+        while (currentRange < intervals.size) {
+            if (intervals[currentRange][0] > end) {
+                result.add(intArrayOf(begin, end))
+                begin = intervals[currentRange][0]
+                end = intervals[currentRange][1]
+            } else if (intervals[currentRange][1] > end) {
+                end = intervals[currentRange][1]
             }
+            currentRange++
         }
-        return list.toTypedArray()
+        result.add(intArrayOf(begin, end))
+        return result.toTypedArray()
     }
 }