This class inherits from the list class and takes two integers as parameters, a and b. a is the length of the list to be created and b is the step or difference between consecutive values and initializes an instance variable length.

It defines a method search which implements the binary search algorithm and takes in the value you are to find as its argument. It returns a dictionary object which contains count, the number of times the function iterated and index, which is the index of the item in the list.