title: What is an efficient algorithm to find whether a singly linked list is circular/cyclic or not?
body: <p>How can I find whether a singly linked list is circular/cyclic or not? I tried to search but couldn't find a satisfactory solution. If possible, can you provide a pseudo-code or Java-implementation?</p>
  
  <p>For instance:<br>
  <code>1</code> → <code>3</code> → <code>5</code> → <code>71</code> → <code>45</code> → <code>7</code> → <code>5</code>, where the second <code>5</code> is actually the third element of the list.</p>