title: Find total number of Increasing Subsequences of given length
body: <p>Given an array of numbers and <strong>question</strong> is to find <strong>total number</strong> of <em>Increasing sub-sequences of length</em> <strong>lis-1</strong>, where <strong>lis</strong> is the length of <code>Largest Increasing sub-sequence</code> of that given array.   </p>
  
  <p><strong>Example:</strong> Suppose the array is <code>5 6 3 4 7 8</code>. Here, <strong>lis =  4</strong>. So, <strong>lis-1 = 3</strong>. Therefore, the total number of sub-sequences are <code>8</code> and  given below: </p>
  
  <pre><code>5 6 7
  5 6 8
  3 4 7 
  3 4 8
  3 7 8
  6 7 8
  5 7 8
  4 7 8
  </code></pre>
  
  <p>Can someone give me an idea for this algorithm, i'm not able to figure it out.</p>