『杭电1608』Centipede Collisions

Problem Description

A small boy named Tommy has some toy centipedes that are a series of 1 centimeter segments. Tommy assembles his centipedes to any length he likes and places them on a 30 x 30 centimeter board that allows the centipedes to travel in 1 centimeter wide tracks that criss-cross the board.

The centipedes travel only parallel to either the x or y axis on the board. Centipede segments of the same centipede advance at the same time and centipedes advance in cyclic numerical order (all of centipede 0 first, then 1, etc.). When more than one segment of two or more centipedes occupy the same x,y coordinate, there is a centipede collision.

Anytime a collision occurs, all segments occupying the collistion site stop and continue to occupy the collision site. All remaining segments on a centipede detach from the segment involved in the collision and continue their march until another collision o