Linked List Cycle

Check whether or not a linked list contains a cycle. If a cycle exists, return TRUE. Otherwise, return FALSE. The cycle means that at least one node can be reached again by traversing the next pointer.

Check whether or not a linked list contains a cycle. If a cycle exists, return TRUE. Otherwise, return FALSE. The cycle means that at least one node can be reached again by traversing the next pointer.

Constraints

Let n be the number of nodes in a linked list.

• 0 ≤ n ≤ 500
• −10⁵ ≤ Node.data ≤ 10⁵

Solution To find cycle in linked list we'll use slow and fast pointer. Fast pointer will travel two nodes at a time while slow pointer will run with one node at a time. if at any point they become equal there is cycle in loop

function detectCycle(head){
let slow= head;
let fast = head;

while(fast!=null &&  fast.next!=null){

slow= slow.next;
fast=fast.next.next;

if(slow===fast){
return true
}
}
return false;

}

Complexity

Time: O(N)

Space: O(1)