Detect_Remove_loop.py

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None


class Linked_List:
    def __init__(self):
        self.head = None

    def Insert_At_End(self, new_data):
        new_node = Node(new_data)
        if self.head is None:
            self.head = new_node
            return
        current = self.head
        while current.next:
            current = current.next
        current.next = new_node

    def Detect_and_Remove_Loop(self):
        slow = fast = self.head
        while slow and fast and fast.next:
            slow = slow.next
            fast = fast.next.next
            if slow == fast:
                self.Remove_loop(slow)
                print("Loop Found")
                return 1
        return 0

    def Remove_loop(self, Loop_node):
        ptr1 = self.head
        while 1:
            ptr2 = Loop_node
            while ptr2.next != Loop_node and ptr2.next != ptr1:
                ptr2 = ptr2.next
            if ptr2.next == ptr1:
                break
            ptr1 = ptr1.next
        ptr2.next = None

    def Display(self):
        temp = self.head
        while temp:
            print(temp.data, "->", end=" ")
            temp = temp.next
        print("None")


if __name__ == "__main__":
    L_list = Linked_List()
    L_list.Insert_At_End(8)
    L_list.Insert_At_End(5)
    L_list.Insert_At_End(10)
    L_list.Insert_At_End(7)
    L_list.Insert_At_End(6)
    L_list.Insert_At_End(11)
    L_list.Insert_At_End(9)
    print("Linked List with Loop: ")
    L_list.Display()
    print("Linked List without Loop: ")
    L_list.head.next.next.next.next.next.next.next = L_list.head.next.next
    L_list.Detect_and_Remove_Loop()
    L_list.Display()