How to make a cycle?

#1

How can we make a cycle, we have not been taught…

#2

Your code is giving runtime error because your circular linked list is not being formed.
Say If INPUT IS 1 2 3 4 5 2 3 -1
form a linked list 1->2->3->4>5 then you see that 2 has already been visited , so connect the next pointer of 5 to 2. This way you have created the circular linked list . After that just detect the cycle, remove the cycle, print the new linked list.
Maintain a map or a visited array…whenever you see that a node is already visited, connect next pointer of previous node to that node.

Do something like this

void buildCycleList(Node *&head)
{
    unordered_map<int, Node *> hash;
    int x;
    cin >> x;
    if (x == -1)
    {
        head = NULL;
        return;
    }
    head = new Node(x);
    hash[x] = head;
    Node *current = head;
    while (x != -1)
    {
        cin >> x;
        if (x == -1)
            break;
        if (hash.find(x) != hash.end())
        {
            current->next = hash[x];
            return;
        }
        Node *n = new Node(x);
        current->next = n;
        current = n;
        hash[x] = n;
    }
    current->next = NULL;
}
#3

I cannot understand your code as we have not been taught map

#4

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