Day 100 - Linked List Cycle
How can we check if a linked list has a cycle in it?  Thereâs a pretty clever way to do it - keep two pointers, one that moves forward by one node (blue), and one the moves forward by two nodes (black).  If thereâs a cycle, then the black node wrap around and âcatchâ the blue node.  If the nodes never overlap, then there canât be a cycle.











