# Leet Code :Linked List Cycle II Java || Python || C++ solution

Given the `head` of a linked list, return the node where the cycle begins. If there is no cycle, return `null`.

There is a cycle in a linked list if there is some node in the list that can be reached again by continuously following the `next` pointer. Internally, `pos` is used to denote the index of the node that tail’s `next` pointer is connected to (0-indexed). It is `-1` if there is no cycle. Note that `pos` is not passed as a parameter.

Do not modify the linked list.

Example 1:

```Input: head = [3,2,0,-4], pos = 1
Output: tail connects to node index 1
Explanation: There is a cycle in the linked list, where tail connects to the second node.

```

Solution:

``````/**
* struct ListNode {
*     int val;
*     ListNode *next;
*     ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:

while(two!=NULL && two->next!=NULL){
one=one->next;
two=two->next->next;
if(one==two){
while(one!=check){
check=check->next;
one=one->next;
}
return one;
}
}
return NULL;

}
};``````