POJ系统第1657题的源程序。在必要的地方附有程序说明-POJ system, the first 1657 title of the source. Where necessary with a descr iption of the procedures

POJ1657,棋盘上的距离问题，计算国际象棋棋盘上由某一点走到某一点所需要的最少步数。-POJ1657, chessboard distance problem, calculated on the international chessboard come from a certain point by a point at least the required steps.