Finding loops/cycles in a linked list

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[@whatever6223]

Is it really necessary to check whether slow != NULL? Can I simply check for (fast->next != NULL && fast->next->next != NULL) ?

[@CodeVault]

That's true, it's enough to check while(fast != NULL && fast->next != NULL)

[@nematkosha6683]

Which site or book would you recommend for linked list structure? i should to study.

[@CodeVault]

I'm really not sure... geeksforgeeks has decent code but it's not the best quality

[@nematkosha6683]

@@CodeVault may I have your email this one is my email ([e-mail]) send me I email i have some problem to help me

[@wassimhaimoudi]

I am having a hard time understanding what would happen if it started looping at node number 3 or 4 basically n>2whereas n is the number of nodes traversed before the first time we encounter a cycle start point. Anyone can help me with that? I tried when n = 3 with 6 nodes total and the first time both pointers intersect at the same location is inside the loop. Basically at node 5. But the problem is the slow pointer didn’t reach the end of the linked list for the first time so we don’t know yet if we are inside a cycle or again since didn’t reach the end from where the cycle loops back which is node 6. Thanks for helping me in advance!

[@CodeVault]

The fast pointer should always find the slower pointer if a loop exists. It could take more than 1 iteration of the loop for the pointers to coincide

[@wassimhaimoudi]

@@CodeVault Thank you for the response! I think I get it now.

[@MonkoGames]

Im getting a segmentation fault in the while loop

[@CodeVault]

What's the code? And also how do you create the linked list?

[@catalinvrabiuta8]

could you put the code from linked lists on a github repository?

[@CodeVault]

The code from all the videos can be found on our website. Here is the link: code-vault.net/lesson/2t4nd0hjh5:1603732280242