Help me in solving LINKLP problem

help
,
1

My issue

Please explain me what’s wrong with my code.
I’m getting runtime error SIGABRT.

sol: sol.cpp:73: int main(): Assertion `connection<n' failed.

My code

int solve(Node* head){
    if(!head){
        return -1;
    }
    if(!head->next){
        return -1;
    }
    Node* slow = head;
    Node* fast = head;
    while(fast && fast->next){
        slow = slow->next;
        fast = fast->next->next;
        if(slow==fast){
            int count=1;
            slow=slow->next;
            while(slow!=fast){
                slow=slow->next;
                count++;
            }
            return count;
        }
    }
    return -1;
}

Learning course: Linked Lists
Problem Link: Count loop length in Linked List Practice Problem in - CodeChef

2

In addition, I am doing exactly what the solution explanation is saying. Please take a look at solution explanation as well:

Explanation

We can use Floyd’s Cycle-Finding Algorithm,

Here’s how you can implement and use the algorithm to find the number of elements in the loop:

  1. Initialize two pointers, slow and fast.
  2. Move the slow pointer by one step and the fast pointer by two steps in each iteration.
  3. If the linked list contains a cycle, the fast pointer will eventually meet the slow pointer within the cycle.
  4. Once the two pointers meet, keep the fast pointer where it is, and move the slow pointer one step at a time until it meets the fast pointer again. While moving the slow pointer, count the number of nodes you have traversed.
  5. The count at which the slow pointer meets the fast pointer again is the number of elements in the loop.
3

@dpcoder_007 bro do you know where the issue is? I still don’t understand this one, or maybe I should assume that this is an issue with the rest of the implemented code behind that is not visible to me

4

@b_suvonov
actually its a pro level course so won’t be able to open the problem .
Same question is on gfg. I Have coded it and got ac.
plzz refer it for better understanding .

int countNodesinLoop(struct Node *head)
{
    // Code here
    if(!head)
    return 0;
    if(!head->next)
    return 0;
    Node* slow = head;
    Node* fast = head;
    int cnt=0;
    while(fast&&fast->next)
    {
        slow=slow->next;
        fast=fast->next->next;
        if(slow==fast)
        {
            slow=slow->next;
            fast=fast->next->next;
            cnt++;
            while(fast!=slow)
            {
                cnt++;
                fast=fast->next;
            }
            break;
        }
    }
    return cnt;
    
}