public GridBoard Clone()
{
GridBoard result = new GridBoard(this.Size);
for (int i = 0; i < Data.Length; i++)
{
for (int j = 0; j < Data.Length; j++)
{
result[i, j] = this[i, j];
}
}
return(result);
}
public static void Main(string[] args)
{
var Board = new GridBoard(Size: 14);//建立棋盤
Stopwatch watch = new Stopwatch();
watch.Start();
var result = KnightTour(Board);
watch.Stop();
Console.WriteLine($"運算耗時:{watch.Elapsed}");
Console.WriteLine(result.ToString());
Console.ReadKey();
}
public static GridBoard KnightTour(GridBoard Board, Point Start, int Step = 0)
{
Board[Start] = ++Step;//將目前座標填入值
if (Step == Board.Size * Board.Size)
{
return(Board); //已經完成巡邏
}
foreach (var NextPoint in Steps //列舉可移動座標並且帶入任務檢驗
.Select(x => x.Move(Start)) //將移動後的座標列出
.Where(x => Board.InBoard(x) && Board.CanMove(x)) //篩選出可以使用的座標(剔除超出邊界與已經使用過的)
.Select(x => {
var NextBoard = Board.Clone(); //複製目前棋盤狀態
NextBoard[x] = Step + 1; //在移動後的位置填寫新的step值
var NextNextMove = (from t in Steps select t.Move(x)).Where(y => NextBoard.InBoard(y) && NextBoard.CanMove(y));
//計算下一節點可移動的路徑集合
return(new { //建立匿名物件
Point = x, //下一階層移動座標
Degree = NextNextMove.Count() //計算下一節點可移動的路徑數量
});
})
.OrderBy(x => x.Degree)//使用可移動數量進行遞增排序
)
{
var NextLevelResult = KnightTour(Board, NextPoint.Point, Step);//使用遞迴並指派下個移動位置
if (NextLevelResult != null)
{
return(NextLevelResult); //如果下一層有回傳結果則代表是可行路徑則回傳下一層結果
}
}
Board[Start] = 0; //如果上面迴圈沒有回傳則代表本層是失敗的，清除本層對盤面的影響
return(null); //回傳結果為空，因為下一步都無法走而為空值
}
public static GridBoard KnightTour(GridBoard Board) => KnightTour(Board, new Point());