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。棋盘上还有一个空格，与空格相邻的棋子可以移到空格中。要求解决的问题是：给出一个初始状态和一个目标状态，找出一种从初始转变成目标状态的移动棋子步数最少的移动步骤。

所谓问题的一个状态就是棋子在棋盘上的一种摆法。棋子移动后，状态就会发生改变。解八数码问题实际上就是找出从初始状态到达目标状态所经过的一系列中间过渡状态。

-The eight digital also known as JiuGongTu. 3 × 3 board, put eight pieces, each piece is marked with a certain number of 1-8, the different pieces on the subject of digital is not the same. Is also a board spaces, and spaces adjacent pieces can be moved to the space. Required to solve the problem is: given an initial state and a target state, to identify the least number of steps to move a pawn move step into a initial target state.

A state of so-called problem is a pawn on the chessboard pendulum method. Pawn move, the status will change. The solution eight digital actually is to find out from the initial state to reach the target state through a series of intermediate transition state.