附原题:(以防乌鸦描述不清,误导大家) Please help the Knight to go from the green castle to the blue castle. Notice that: There are 4 lines of square columns between this two castles that have to be passed. The only way to pass is to touch all the square columns once & end up with the same spot you started with. The Knight step must be like a knight step in chess. help: A Knight step in chess: 2 square forward & 1 square to the right [res]OR left.