linkedlisthrc.py

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

class SinglyLinkedList:
    def __init__(self):
        self.head = None
        self.tail = None

    def insert_node(self, node_data):
        node = SinglyLinkedListNode(node_data)

        if not self.head:
            self.head = node
        else:
            self.tail.next = node


        self.tail = node

def print_singly_linked_list(node, sep):
    while node:
        print(str(node.data), end='')

        node = node.next

        if node:
            print(sep, end='')

    print()

# Complete the has_cycle function below.

#
# For your reference:
#
# SinglyLinkedListNode:
#     int data
#     SinglyLinkedListNode next
#
#
def has_cycle(head):
    if head:
        current = head
        elements = []
        while current:
            # Treat data like address:
            address = id(current)
            print(f'Processing {current.data} at address {address}...')
            if address in elements:
                return 1
            elements.append(address)
            current = current.next

    return 0

if __name__ == '__main__':
    tests = int(input())

    for _ in range(tests):
        index = int(input())

        llist_count = int(input())

        llist = SinglyLinkedList()

        for _ in range(llist_count):
            llist_item = int(input())
            llist.insert_node(llist_item)

        extra = SinglyLinkedListNode(-1);
        temp = llist.head;

        for i in range(llist_count):
            if i == index:
                extra = temp

            if i != llist_count-1:
                temp = temp.next

        temp.next = extra

        result = has_cycle(llist.head)

        print(str(int(result)))