Write a scheme problem that solves the following (from the Eastern Regional
ACM Programming Contest).

Given an 8 x 8 chessboard, with rows numbered 1-8 from top to bottom on the
left side, and columns numbered from 1-8 from left to right on the top
side, any square can be identified by a pair (x,y). e.g. (1,8) is the
top right corner.

Write a scheme function Knight that determines the minimum number of moves
of a knight to get from one square to another. For example

  (Knight (1 1) (1 3)) yields 2

since  you can get from square 1,1 to square 1,3 in two moves. I wlil
provide sample data later.

A knight moves either 2 squares in a straight line, and then 1 square
perpendicuilar to this line, or 1 square and then two squares
perpendicular.

e.g. from square 4,4
all the following can be done in one move

6,5
6,3
2,5
2,3
3,6
3,2
5,6
5,2

Restrictions:

*Your solution may not contain _any_ loops or assignments!*

This is due on the day of the exam, December 15th

hint this is basically a simple recursive tree search, to find a minimum
path.