cycle detection in linked list added

Cpp/CycleDetection_InLinkedList.cpp

@@ -0,0 +1,98 @@
+#include <iostream>
+#include <bits/stdc++.h>
+using namespace std;
+// ! Definition for a node of linked list
+class Node
+{
+public:
+    int data;
+    Node *next;
+    Node(int data)
+    {
+        this->data = data;
+        this->next = NULL;
+    }
+};
+
+// ! Definition for a linked list
+class LinkedList
+{
+public:
+    Node *head;
+    LinkedList()
+    {
+        this->head = NULL;
+    }
+    void insert(int data)
+    {
+        Node *newNode = new Node(data);
+        if (head == NULL)
+        {
+            head = newNode;
+            return;
+        }
+        Node *temp = head;
+        while (temp->next != NULL)
+        {
+            temp = temp->next;
+        }
+        temp->next = newNode;
+    }
+    void print()
+    {
+        Node *temp = head;
+        while (temp != NULL)
+        {
+            cout << temp->data << " ";
+            temp = temp->next;
+        }
+        cout << endl;
+    }
+    void isCycle()
+    {
+        Node *slow = head;
+        Node *fast = head;
+        while (fast != NULL && fast->next != NULL)
+        {
+            slow = slow->next;
+            fast = fast->next->next;
+            if (slow == fast)
+            {
+                cout << "Cycle is present" << endl;
+                return;
+            }
+        }
+        cout << "Cycle is not present" << endl;
+    }
+};
+
+int main()
+{
+    // ! let's first create a linked linked list.
+    LinkedList *list = new LinkedList();
+    list->insert(1);
+    list->insert(2);
+    list->insert(3);
+    list->insert(4);
+    list->insert(5);
+    list->insert(6);
+    list->insert(7);
+
+    // printing the list before adding a cyle
+    cout << "Linked list before adding a cycle" << endl;
+    list->print();
+    // adding a cycle in the linked list for testing purpose.
+    // ! for now the linked list is something like below
+    // 1-> 2-> 3-> 4-> 5-> 6-> 7-> 4 -> 5 -> 6-> 7-> 4 and so on.. beccause of the cycle.
+    list->head->next->next->next->next->next->next->next = list->head->next->next->next;
+
+    // now we call Floyd Marshal's cycle finding algorithm to find the cycle in the linked list.
+    list->isCycle();
+    return 0;
+}
+
+// HOW THE ALGO WORKS
+// Basically we have a slow pointer that moves one step at a time and a fast pointer that moves two steps at a time.
+// If there exists a cycle then there is a guarantee that the slow pointer and the fast pointer will meet at some point.
+// If they meet then exit the loop and return true.
+// Else if one of them becomes null then return false.