ChessBoard

PROBLEM STATEMENT

The chessboard is an 8 by 8 grid of squares.  For the purpose of this problem
consider the rows of the chessboard to be numbered from 1 to 8 starting at the
top and moving down, and the columns to be numbered from 1 to 8 starting at the
left and moving right.  Board positions will be identified by (row,column)
ordered pairs.

The knight is a chess piece capable of moving exactly two squares in one
direction and then one square perpendicularly.  Assuming the board is empty
except for a knight, the problem is to determine the minimum number of moves
required to move from point A to point B on the board. 

DEFINITION
Class name: ChessBoard
Method name: getMinMoves
Parameters: String
Return type: int

Method signature: int getMinMoves(String pos); Be sure your method is public.

Each test case contains 4 integers in the range 1 to 8, delimited by one or
more spaces, representing the row and column of the starting position on the
board, and the row and column of the destination position, respectively.  For
each test case, return the minimum number of moves required to reach the
destination position from the starting position.

TopCoder will ensure that:
* all positions given are valid positions on a chess board.
* the input will be of the form (quotation marks are included for clarity only)
"int int int int", where there is one or more spaces between each int. Each int
must be between 1 and 8 inclusive. 

NOTES
* if the starting position and the destination position are the same, the
number of moves is zero.
* the knight cannot move diagonally.

EXAMPLES
1. Given the position string "5 5 4 5", the minimum number of moves to get from
position (5, 5) to position (4, 5) is 3.

2. Given the position string "3 1 3 8", the minimum number of moves to get from
position (3, 1) to position (3, 8) is 5.