title: Successor and Predecessor worst-case running time in dynamic sets
body: <p>What is the asymptotic worst-case running time for the following dynamic-set operations ? </p>
  
  <p>Successor(L,x) for unsorted singly &amp; doubly linked lists </p>
  
  <p>Predecessor(L,x) for unsorted doubly linked list </p>
  
  <p>L: list , x: pointer to an entry </p>
  
  <p>(Actually this is part of the question 10-1 of the book : "Introduction to Algorithms, third edition" , I searched for the answer , the answer is O(n) but I couldn't find any explanation for it) </p>