和为15的棋盘游戏

public class grid15{
int[][]board;
grid15()
{board=new int[3][3];}     //构造方法结束
public static void main(String[]args){
grid15 a=new grid15();
for(a.initdata();a.board[0][0]!=9;a.nextdata())
if(a.check())
{a.outputlines();System.out.println();}
a.initdata();
a.board[0][0]=9;
for(;a.board[0][0]!=1;a.nextdata())
    if(a.check())
    {a.outputlines();System.out.println();}
}
public boolean check(){
if(!datadifferent())
    return (false);
for(int i=0;i<board.length;i++)
    if((board[0][i]+board[1][i]+board[2]
[i]!=15)||(board[i][0]+board[i][1]+board[i][2]!=15)||(board[0]
[0]+board[1][1]+board[2][2]!=15)||(board[2][0]+board[1][1]+board[0]
[2]!=15))
   return false;

return (true);
}
public boolean datadifferent(){
int[]digit=new int[10];
for(int i=0;i<board.length;i++)
    for(int j=0;j<board.length;j++)
        digit[board[i][j]]=1;
int j=0;
for(int i=0;i<digit.length;i++)
j+=digit[i];
if(j==9)
    return (true);
return (false);
}
public void nextdata(){
for(int i=2;i>=0;i--)
    for(int j=2;j>=0;j--)
        if(board[i][j]==9)
            board[i][j]=1;
        else
        {board[i][j]++;return;}
}
public void initdata(){
int i,j,k;
for(i=0,k=1;i<board.length;i++)
    for(j=0;j<board.length;j++,k++)
        board[i][j]=k;
}
private void outputlines(){
for(int i=0;i<board.length;i++){
outputline();
outputline(i);
}
outputline();
}
private void outputline(){
System.out.println("+-----+");
}
private void outputline(int i){
int j;
for(j=0;j<board[i].length;j++)
System.out.print("|"+board[i][j]);
System.out.println("|");
}

}