Reverse Linked List in Group of k

Bogdan Hladiuc · Bogdan Hladiuc · commit 63e9c10069f4 · 2022-10-04T22:17:17.000-04:00
diff --git a/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj b/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\Library\Library.csproj" />
+  </ItemGroup>
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>
diff --git a/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/ReverseKGroup.cs b/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/ReverseKGroup.cs
@@ -0,0 +1,120 @@
+﻿#nullable disable warnings
+using System.Diagnostics;
+using Library;
+
+namespace Formation {
+
+    public class ReverseKGroup {
+        public static void Run() {
+            var test = new Test {
+                Id = 1,
+                K = 2,
+                List = new SingleLinkedListNode(1,
+                    new SingleLinkedListNode(2,
+                    new SingleLinkedListNode(3,
+                    new SingleLinkedListNode(4,
+                    new SingleLinkedListNode(5, null))))),
+                Expected = new SingleLinkedListNode(2,
+                        new SingleLinkedListNode(1,
+                        new SingleLinkedListNode(4, 
+                        new SingleLinkedListNode(3,
+                        new SingleLinkedListNode(5, null)))))
+            };
+
+            test.List.Print();
+            var result = Reverse(test.List, test.K);
+            result.Print();
+            test.Verify(result);
+        }
+        
+        private static SingleLinkedListNode ReverseKGroups(SingleLinkedListNode head, int k) {
+            var curr = head;
+            var count = 0;
+            
+            while (curr != null && count < k) {
+                count++;
+                curr = curr.Next;
+            }
+
+            if (count == k) {
+                var reversedHead = ReverseLinkedList(head, k);
+                head.Next = ReverseKGroups(curr, k);
+                return reversedHead;
+            }
+
+            return head;
+        }
+        
+        private static SingleLinkedListNode Reverse(SingleLinkedListNode head, int k) {
+            SingleLinkedListNode newHead = null;
+            SingleLinkedListNode tail = null;
+            var ptr = head;
+            
+            while (ptr != null) {
+                var count = 0;
+                ptr = head;
+                
+                while (count < k && ptr != null) {
+                    ptr = ptr.Next;
+                    count++;
+                }
+                
+                if (count == k) {
+                    var revHead = ReverseLinkedList(head, k);
+
+                    if (newHead == null) {
+                        newHead = revHead;
+                    }
+                    
+                    if (tail != null) {
+                        tail.Next = revHead;
+                    }
+
+                    tail = head;
+                    head = ptr;
+                }
+            }
+            
+            if (tail != null) {
+                tail.Next = head;
+            }
+
+            return newHead ?? head;
+        }
+        
+        private static SingleLinkedListNode ReverseLinkedList(SingleLinkedListNode head, int k) {
+            SingleLinkedListNode newHead = null;
+            var curr = head;
+
+            while (k > 0) {
+                var nextNode = curr.Next;
+                curr.Next = newHead;
+                newHead = curr;
+                curr = nextNode;
+                k--;
+            }
+            
+            return newHead;
+        }
+    }
+    
+    internal class Test {
+        public int Id { get; set; }
+        public int K { get; set; }
+        public SingleLinkedListNode List { get; set; }
+        public SingleLinkedListNode Expected { get; set; }
+        
+        public void Verify(SingleLinkedListNode result) {
+            Debug.Assert(CheckList(result), $"Test {Id} failed.");
+        }
+        
+        private bool CheckList(SingleLinkedListNode result) {
+            while (Expected != null && result != null && Expected.Val == result.Val) {
+                Expected = Expected.Next;
+                result = result.Next;
+            }
+
+            return Expected == null && result == null;
+        }
+    }
+}
diff --git a/LeetcodeNew.sln b/LeetcodeNew.sln
@@ -89,6 +89,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Day_1_Remove_Delete_Middle_
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Day_2_Spiral_Traversal_Q54", "Formation\21_Days_Challenge\Day_2_Spiral_Traversal_Q54\Day_2_Spiral_Traversal_Q54.csproj", "{82FE764B-4AA7-4694-B9BC-85119629AF56}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Day_3_Reverse_Groups_of_K_Nodes_Q25", "Formation\21_Days_Challenge\Day_3_Reverse_Groups_of_K_Nodes_Q25\Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj", "{4936F68E-2FB8-4DC3-96CF-53116D2437E6}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -594,10 +596,23 @@ Global
 		{82FE764B-4AA7-4694-B9BC-85119629AF56}.Release|x64.Build.0 = Release|Any CPU
 		{82FE764B-4AA7-4694-B9BC-85119629AF56}.Release|x86.ActiveCfg = Release|Any CPU
 		{82FE764B-4AA7-4694-B9BC-85119629AF56}.Release|x86.Build.0 = Release|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Debug|x64.Build.0 = Debug|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Debug|x86.Build.0 = Debug|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Release|x64.ActiveCfg = Release|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Release|x64.Build.0 = Release|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Release|x86.ActiveCfg = Release|Any CPU
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{45EB27A3-9FBB-48ED-8C89-E0F074C02E8C} = {71C7D88B-6D5D-4E25-A275-869603700831}
 		{F4D0F4C2-26A6-43AC-BC80-D1762684A605} = {45EB27A3-9FBB-48ED-8C89-E0F074C02E8C}
 		{82FE764B-4AA7-4694-B9BC-85119629AF56} = {45EB27A3-9FBB-48ED-8C89-E0F074C02E8C}
+		{4936F68E-2FB8-4DC3-96CF-53116D2437E6} = {45EB27A3-9FBB-48ED-8C89-E0F074C02E8C}
 	EndGlobalSection
 EndGlobal
diff --git a/Run/Program.cs b/Run/Program.cs
@@ -4,8 +4,9 @@ static void Main(string[] args) {
 
             #region Formation
 
-            //Formation.DeleteMiddleNode.Run(); // Day 1
-            Formation.SpiralTraversal.Run(); // Day 2
+            // Formation.DeleteMiddleNode.Run(); // Day 1
+            // Formation.SpiralTraversal.Run(); // Day 2
+            Formation.ReverseKGroup.Run(); // Day 3
 
             #endregion Formation
 
diff --git a/Run/Run.csproj b/Run/Run.csproj
@@ -42,6 +42,7 @@
     <ProjectReference Include="..\Q242_Valid_Anagram\Q242_Valid_Anagram.csproj" />
     <ProjectReference Include="..\Formation\21_Days_Challenge\Day_1_Remove_Delete_Middle_Node_Q2095\Day_1_Remove_Delete_Middle_Node_Q2095.csproj" />
     <ProjectReference Include="..\Formation\21_Days_Challenge\Day_2_Spiral_Traversal_Q54\Day_2_Spiral_Traversal_Q54.csproj" />
+    <ProjectReference Include="..\Formation\21_Days_Challenge\Day_3_Reverse_Groups_of_K_Nodes_Q25\Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj" />
   </ItemGroup>
 
   <PropertyGroup>
diff --git a/Run/obj/Run.csproj.nuget.dgspec.json b/Run/obj/Run.csproj.nuget.dgspec.json
@@ -172,6 +172,62 @@
         }
       }
     },
+    "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj": {
+      "version": "1.0.0",
+      "restore": {
+        "projectUniqueName": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj",
+        "projectName": "Day_3_Reverse_Groups_of_K_Nodes_Q25",
+        "projectPath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj",
+        "packagesPath": "/Users/Bogdan/.nuget/packages/",
+        "outputPath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/obj/",
+        "projectStyle": "PackageReference",
+        "configFilePaths": [
+          "/Users/Bogdan/.nuget/NuGet/NuGet.Config"
+        ],
+        "originalTargetFrameworks": [
+          "net6.0"
+        ],
+        "sources": {
+          "https://api.nuget.org/v3/index.json": {}
+        },
+        "frameworks": {
+          "net6.0": {
+            "targetAlias": "net6.0",
+            "projectReferences": {
+              "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Library/Library.csproj": {
+                "projectPath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Library/Library.csproj"
+              }
+            }
+          }
+        },
+        "warningProperties": {
+          "warnAsError": [
+            "NU1605"
+          ]
+        }
+      },
+      "frameworks": {
+        "net6.0": {
+          "targetAlias": "net6.0",
+          "imports": [
+            "net461",
+            "net462",
+            "net47",
+            "net471",
+            "net472",
+            "net48"
+          ],
+          "assetTargetFallback": true,
+          "warn": true,
+          "frameworkReferences": {
+            "Microsoft.NETCore.App": {
+              "privateAssets": "all"
+            }
+          },
+          "runtimeIdentifierGraphPath": "/usr/local/share/dotnet/sdk/6.0.202/RuntimeIdentifierGraph.json"
+        }
+      }
+    },
     "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Library/Library.csproj": {
       "version": "1.0.0",
       "restore": {
@@ -2263,6 +2319,9 @@
               "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_2_Spiral_Traversal_Q54/Day_2_Spiral_Traversal_Q54.csproj": {
                 "projectPath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_2_Spiral_Traversal_Q54/Day_2_Spiral_Traversal_Q54.csproj"
               },
+              "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj": {
+                "projectPath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj"
+              },
               "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Library/Library.csproj": {
                 "projectPath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Library/Library.csproj"
               },
diff --git a/Run/obj/project.assets.json b/Run/obj/project.assets.json
@@ -41,6 +41,19 @@
           "bin/placeholder/Day_2_Spiral_Traversal_Q54.dll": {}
         }
       },
+      "Day_3_Reverse_Groups_of_K_Nodes_Q25/1.0.0": {
+        "type": "project",
+        "framework": ".NETCoreApp,Version=v6.0",
+        "dependencies": {
+          "Library": "1.0.0"
+        },
+        "compile": {
+          "bin/placeholder/Day_3_Reverse_Groups_of_K_Nodes_Q25.dll": {}
+        },
+        "runtime": {
+          "bin/placeholder/Day_3_Reverse_Groups_of_K_Nodes_Q25.dll": {}
+        }
+      },
       "Library/1.0.0": {
         "type": "project",
         "framework": ".NETCoreApp,Version=v6.0",
@@ -502,6 +515,11 @@
       "path": "../Formation/21_Days_Challenge/Day_2_Spiral_Traversal_Q54/Day_2_Spiral_Traversal_Q54.csproj",
       "msbuildProject": "../Formation/21_Days_Challenge/Day_2_Spiral_Traversal_Q54/Day_2_Spiral_Traversal_Q54.csproj"
     },
+    "Day_3_Reverse_Groups_of_K_Nodes_Q25/1.0.0": {
+      "type": "project",
+      "path": "../Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj",
+      "msbuildProject": "../Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj"
+    },
     "Library/1.0.0": {
       "type": "project",
       "path": "../Library/Library.csproj",
@@ -698,6 +716,7 @@
       "Counting_Sort >= 1.0.0",
       "Day_1_Remove_Delete_Middle_Node_Q2095 >= 1.0.0",
       "Day_2_Spiral_Traversal_Q54 >= 1.0.0",
+      "Day_3_Reverse_Groups_of_K_Nodes_Q25 >= 1.0.0",
       "Library >= 1.0.0",
       "Q10_Regular_Expression_Matching >= 1.0.0",
       "Q1249_Minimum_Remove_To_Make_Valid_Parentheses >= 1.0.0",
@@ -772,6 +791,9 @@
             "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_2_Spiral_Traversal_Q54/Day_2_Spiral_Traversal_Q54.csproj": {
               "projectPath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_2_Spiral_Traversal_Q54/Day_2_Spiral_Traversal_Q54.csproj"
             },
+            "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj": {
+              "projectPath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Formation/21_Days_Challenge/Day_3_Reverse_Groups_of_K_Nodes_Q25/Day_3_Reverse_Groups_of_K_Nodes_Q25.csproj"
+            },
             "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Library/Library.csproj": {
               "projectPath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Library/Library.csproj"
             },
diff --git a/Run/obj/project.nuget.cache b/Run/obj/project.nuget.cache
@@ -1,6 +1,6 @@
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+  "dgSpecHash": "PExtQsV6jTLun2CfiLPD9yz1kLS7Hk4gTRIUiljlED5qv3OIiL3AuVeIKs/t6R094YBHKmxVO46LAHmgfXk/PQ==",
   "success": true,
   "projectFilePath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Run/Run.csproj",
   "expectedPackageFiles": [],

Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`{`
`2`	`2`	`"version": 2,`
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`4`	`4`	`"success": true,`
`5`	`5`	`"projectFilePath": "/Users/Bogdan/Documents/Work/CtCI/VS_Code/LeetcodeNew/Run/Run.csproj",`
`6`	`6`	`"expectedPackageFiles": [],`