残缺棋盘问题

	//tr子棋盘左上角方格所在行
	//tc子棋盘左上角方格所在列
	//dr残缺方块所在行
	//dc残缺方块所在列
	//size棋盘的行数或列数
	int amount=0,board[maxn][maxn];
	void cover(int tr,int tc,int dr,int dc,int size){
	        
         if(size<2)return;
		 amount++;
		 int t=amount;
		 int s=size/2;
		 if(dr<tr+s&&dc<tc+s){//残缺格子在左上的方格里
		 cover(tr,tc,dr,dc,s);
		 board[tr+s][tc+s-1]=t;
		 board[tr+s][tc+s]=t;
		 board[tr+s-1][tc+s]=t;
		 cover(tr,tc+s,tr+s-1,tc+s,s);
		 cover(tr+s,tc,tr+s,tc+s-1,s);
		 cover(tr+s,tc+s,tr+s,tc+s,s);
		 
		 }
		 else if(dr>=tr+s&&dc<tc+s){//左下
		 cover(tr+s,tc,dr,dc,s);
		 board[tr+s-1][tc+s-1]=t;
		 board[tr+s-1][tc+s]=t;
		 board[tr+s][tc+s]=t;
		 cover(tr,tc,tr+s-1,tc+s-1,s);
		 cover(tr,tc+s,tr+s-1,tc+s,s);
	         ……	 
		 }
		}