Day7

141. Linked List Cycle/141. Linked List Cycle.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <RootNamespace>_141._Linked_List_Cycle</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

141. Linked List Cycle/ListNode.cs

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+namespace _141._Linked_List_Cycle;
+
+//Definition for singly-linked list.
+public class ListNode
+{
+    public int val;
+    public ListNode? next;
+    public ListNode(int x)
+    {
+        val = x;
+        next = null;
+    }
+}
+

141. Linked List Cycle/Program.cs

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+namespace _141._Linked_List_Cycle;
+
+internal class Program
+{
+    static void Main(string[] args)
+    {
+        Console.WriteLine("Hello, World!");
+    }
+}

141. Linked List Cycle/Solution.cs

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+namespace _141._Linked_List_Cycle;
+
+public class Solution
+{
+    public bool HasCycle(ListNode head)
+    {
+        if (head == null)
+            return false;
+        ListNode? cur = head;
+        int bit = 1 << 28;
+        int curAbs = 0;
+        while (cur != null && (curAbs & bit) == 0)
+        {
+            cur.val ^= bit;
+            cur = cur.next;
+            if (cur != null)
+                curAbs = cur.val < 0 ? (cur.val * -1) : cur.val;
+        }
+        if ((curAbs & bit) != 0)
+            return true;
+        return false;
+    }
+}