马的遍历执行过程中 需要输入可执行文件 不懂 程序如下

马的遍历执行过程中 需要输入可执行文件 不懂 请指教 程序如下
struct Elem
{ char c;
  int mark_direct[8];
  };

  Elem chessboard[12][12];
  struct direct_increment
  { int dx;
  int dy;
};
struct Postion
{ int x;
  int y;
  };
direct_increment direct_ar[8]={{1,2},{2,1},{2,-1},{1,-2},{-1,-2},{-2,-1},{-2,1},{-1,2}};
void init_chessboard(Elem(*p)[12])
{
  for(int i=0;i<12;i++)
  for(int j=0;j<12;j++)
p[i][j].c='#';
  
  for(i=2;i<9;i++)
  for(int j=2;j<=9;j++)
{ (p[i][j]).c='0';
for(int k=0;k<8;k++)
((p[i][j]).mark_direct[k])[k]=0;
}
}
bool check_postion(Postion pos)
{
  if(pos.x<2||pos.x>9||pos.y<2||pos.y>9)return false;
  else return ture;
  }
bool is_last_point(Elem(*P)[12],Postion pos)
{
  char cc=p[pos.x][pos.y].c;
  if(cc=='1')return false;
  else
  for(int i=2;i<=9;i++)
for(int j=2;j<=9;j++)
if(p[i][j].c=='0'&&!(i==pos.x&&pos.y)) return false;
return true;
}
int count_way(Postion pos)
{
int counter=0;
for(int i=0;i<8;i++)
{
  Poation pos1;
  pos1.x=pos.x+direct_ay[i].dx;
  pos1.y=pos.y+direct_ay[i].dy;
  if((chessboard[pos.x][pos.y].mark_direct)[i]==0&&(chessboard[pos.x+direct_ay[i].dx][pos.y+direct_ay[i].dy]).c=='0')
  ++counter;
  }
  return counter;
}
bool Select_bestpost(Postion *ppos,Postion *bpos)
{
  int ct;int i;int direct,direct_ct=8;
  Postion pos1,pos_best;
  int flag=0;
  for(i=0;i<8;i++)
  {
   
  if(((chessboard[ppos->x][ppos->y]).mark_direct)[i]==0)
{ pos1.x=ppos->x+direct_ay[i].dx;
pos1.y=ppos->y+direct_ay[i].dy;
if(check_postion(pos1)&&!is_visited(chesssboard,pos1))
  if(is_point(chessboard pos1))ct=1;
else
ct=count_way(pos1);
else ct=-1;
if(ct<=direct_ct&&ct>0)
{
pos_best.x=pos1.x;
pos_best.y=pos1.y;
flag=1;
direct_ct=ct;
direct=i;
}
}
else continue;
}
if(flag)
{
bpos->x=pos_best.x;
bpos->y=pos_best.y;
int reverse_direct=(direct)>=4?direct-4:direct+4;
(chessboard[ppos->x][ppos->y]).mark_direct[direct]=1;
(chessboard[ppos->x][ppos->y]).mark_direct[reverse_direct]=1;

return true;
}
else
  return false;
}
bool Visit_Recursion(Elem(*p)[12],Postion pos)
{ Postion next_pos;
  static Poation pos_beg=pos;
  int Succ=0;static ct=0;
  int i;
  mark_step(chessboard,pos);
  if(visit_complete(chessboard))
  { Succ=1;
  ct=0;
return true;
  }
  else
  for(i=0;Succ&&i<8;i++)
{  
if(!Select_bestpost(&pos,&next_pos))continue;
if(!Visit_Recursion(p,ext_pos))
{  
clear_pos(p,next_pos);
continue;
  }
else Succ=1;
++ct;
printf("<=%d:%d",next_pos.x,next_pos.y);
  if(ct%8==0)printf("\n");
  }
void main()
{ Postion pos1;
  char ch;
  init_chessboard(chessboard);
  while(1)
  {
  printf("输入马在棋盘中的起始位置，可以随便设置(2<=x<=9,2<=y<=9)\n");
printf("输入的两个位置用空格分隔，用Enter键确认\n");
scanf("%d%d",&pos1.x,&pos1.y);
if(Visit_Recursion(chessboard,pos1))
{
printf("<=%d:%d\n",pos1.x,pos1.y);