title: increasing decreasing sequence
body: <p>A sequence in which the value of elements first decrease and then increase is called V- Sequence. In a valid V-Sequence there should be at least one element in the decreasing and at least one element in the increasing arm.</p>
  
  <p>For example, "5 3 1 9 17 23" is a valid V-Sequence having two elements in the decreasing arm namely 5 and 3, and 3 elements in the increasing arm namely 9, 17 and 23 . But none of the sequence "6 4 2" or "8 10 15" are V-Sequence since "6 4 2" has no element in the increasing part while "8 10 15" has no element in the decreasing part.</p>
  
  <p>Given a sequence of N numbers find its longest (not necessarily contiguous) sub-sequence which is a V-Sequence ?</p>
  
  <p>Is it possible to do this in O(n)/O(logn)/O(n^2) ?</p>