八数码问题也称为九宫问题。在3×3的棋盘，摆有八个棋子，每个棋子上标有1至8的某一数字，不同棋子上标的数字不相同。-8 digital issues the problem is also known as Nine-palace. In the 3 × 3 chessboard, before there are eight pieces, each piece marked a 1-8 figures, the number of different pieces on the subjec