前言
马踏棋盘 概念在这,不做过多复述。
https://baike.sogou.com/v58959803.htm?fromTitle=马踏棋盘
思路是这样子的,一匹马有上面几种做法,然后进行尝试,然后回溯即可。
我的测试结果是没有用贪心用了 10分钟,用贪心 20秒不到。
正文
class Program
{
//棋盘列数
public static int X;
//棋盘行数
public static int Y;
//标志棋盘的各个位置是否被访问
private static bool[] visited;
//是否访问成功
private static bool finished;
public static Point Override { get; private set; }
static void Main(string[] args)
{
X = 8;
Y = 8;
int row = 1; //马儿初始位置的行,从1开始编号
int column = 1; //马儿初始位置的列,从1开始编号
//创建棋盘
int[,] chessboard = new int[X, Y];
visited = new bool[X * Y];//初始值都是false
Stopwatch stopwatch = new Stopwatch();
stopwatch.Start();
traversalChessboard(chessboard, row - 1, column - 1, 1);
stopwatch.Stop();
for (int i = 0; i < X - 1; i++)
{
for (int j = 0; j < Y - 1; j++)
{
Console.Write(chessboard[i, j] + " ");
}
Console.WriteLine();
}
Console.Read();
}
public static void traversalChessboard(int[,] chessboard, int row, int column, int step)
{
//Thread.Sleep(500);
//第几步
chessboard[row, column] = step;
Console.WriteLine("走x轴"+row+"y轴:"+column);
//表示这个点被访问了
visited[row * X + column] = true;
List<Point> ps = next(new Point(column, row));
sort(ps);
while (ps.Count != 0)
{
Point p = ps[0];
ps.Remove(p);
if (!visited[p.Y * X + p.X])
{
traversalChessboard(chessboard, p.Y, p.X, step + 1);
}
}
if (step < X * Y && !finished)
{
Console.WriteLine("重置x轴" + row + "y轴:" + column);
//如果没有完成回溯重置
chessboard[row,column] = 0;
visited[row * X + column] = false;
}
else
{
finished = true;
}
}
public class Point {
public Point(int x,int y)
{
this.X = x;
this.Y = y;
}
public Point()
{
}
public int X
{
set;
get;
}
public int Y
{
set;
get;
}
}
public static List<Point> next(Point curPoint)
{
List<Point> points = new List<Point>();
Point point6 = new Point();
//显示5位置
if ((point6.X = curPoint.X - 2) >= 0 && (point6.Y = curPoint.Y - 1) >= 0)
{
points.Add(point6);
}
Point point7 = new Point();
//显示6位置
if ((point7.X = curPoint.X - 1) >= 0 && (point7.Y = curPoint.Y - 2) >= 0)
{
points.Add(point7);
}
Point point8 = new Point();
//显示7位置
if ((point8.X = curPoint.X + 1) < X && (point8.Y = curPoint.Y - 2) >= 0)
{
points.Add(point8);
}
Point point1 = new Point();
//显示0位置
if ((point1.X = curPoint.X + 2) <X && (point1.Y = curPoint.Y - 1) >= 0)
{
points.Add(point1);
}
Point point2 = new Point();
//显示1位置
if ((point2.X = curPoint.X + 2) <X && (point2.Y = curPoint.Y + 1) < Y)
{
points.Add(point2);
}
Point point3 = new Point();
//显示2位置
if ((point3.X = curPoint.X + 1) <X && (point3.Y = curPoint.Y + 2) <Y)
{
points.Add(point3);
}
Point point4 = new Point();
//显示3位置
if ((point4.X = curPoint.X - 1) >= 0 && (point4.Y = curPoint.Y + 2) < Y)
{
points.Add(point4);
}
Point point5 = new Point();
//显示4位置
if ((point5.X = curPoint.X - 2) >= 0 && (point5.Y = curPoint.Y + 1) < Y)
{
points.Add(point5);
}
return points;
}
//根据当前这个一步的所有的下一步的选择位置,进行非递减排序, 减少回溯的次数
public static void sort(List<Point> ps)
{
ps.Sort(new companer());
}
public class companer : IComparer<Point>
{
public int Compare(Point x, Point y)
{
int count1 = next(x).Count;
//获取到o2的下一步的所有位置个数
int count2 = next(y).Count;
if (count1 < count2)
{
return -1;
}
else if (count1 == count2)
{
return 0;
}
else
{
return 1;
}
}
}
}
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