Johnson Trotter Algorithm

Question

Overview:

I am trying to implement the Johnson Trotter Algorithm in Java so that I can solve a problem on Project Euler. I have looked and looked bu

Answer 1

Although you are not posting the complete code here (how you decide if an element is mobile or immobile would be helpful), I suspect your error comes from here:

 public int getLargestMobileIndex(ArrayList elements)
      {
         int maxIndex = 0;

         for(int i = 0; i < elements.size(); i++)
         {
            if(elements.get(i).isMobile() && i > maxIndex) //<---------- It seems that 
            // you should compare the i-th element to the maxIndex-th element, not i and
            // maxIndex
            {
               maxIndex = i;
            }
         }

         return maxIndex;
      }

Since the algorithm said find the largest mobile element K.

Also, I suspect there are problems for your isMobile method, but cannot be sure.

Hope this helps!