/// <summary>
/// 读取最短路径
/// </summary>
/// <param name="path">路径</param>
/// <param name="start">开始</param>
/// <param name="end">结束</param>
public void GetShortest(ref List <string> path, MazePointer start, MazePointer end)
{
if (end.X == start.X && end.Y == start.Y)
{
path.Add(MazeGraph[end.X, end.Y]);
return;
}
var endPointer = VisitedList.FirstOrDefault(x => x.X == end.X && x.Y == end.Y);
path.Add(MazeGraph[endPointer.X, endPointer.Y]);
GetShortest(ref path, start, endPointer.Father);
}
/// <summary>
/// 判断是否更短
/// </summary>
/// <param name="current"></param>
/// <param name="next"></param>
/// <returns></returns>
private MazePointer GetShorter(MazePointer current, MazePointer next)
{
if (current == null)
{
return(next);
}
if (next == null)
{
return(current);
}
if (current.H + current.W <= next.H + next.W)
{
return(current);
}
return(next);
}
public void AStar(MazePointer start, MazePointer end)
{
MazePointer initPointer(int x, int y)
{
return(new MazePointer()
{
X = x,
Y = y,
Father = start,
W = GetW(end.X - x, end.Y - y),
H = start.H + 1
});
}
if (start == null || start.Equals(end))
{
return;
}
VisitedList.Add(start);
BackUpList.Remove(start);
//找到strat周围的点
MazePointer current = null, top = null, bottom = null, left = null, right = null;
if (start.Y - 1 >= 0)
{
if (MazeGraph[start.X, start.Y - 1] != null)
{
top = initPointer(start.X, start.Y - 1);
if (VisitedList.Exists(x => x.X == top.X && x.Y == top.Y))
{
top = null;
}
if (top != null)
{
BackUpList.Add(top);
}
current = top;
}
}
if (start.Y + 1 < MazeGraph.GetLength(1))
{
if (MazeGraph[start.X, start.Y + 1] != null)
{
bottom = initPointer(start.X, start.Y + 1);
if (VisitedList.Exists(x => x.X == bottom.X && x.Y == bottom.Y))
{
bottom = null;
}
if (bottom != null)
{
BackUpList.Add(bottom);
}
current = GetShorter(current, bottom);
}
}
if (start.X - 1 >= 0)
{
if (MazeGraph[start.X - 1, start.Y] != null)
{
left = initPointer(start.X - 1, start.Y);
if (VisitedList.Exists(x => x.X == left.X && x.Y == left.Y))
{
left = null;
}
if (left != null)
{
BackUpList.Add(left);
}
current = GetShorter(current, left);
}
}
if (start.X + 1 < MazeGraph.GetLength(0))
{
if (MazeGraph[start.X + 1, start.Y] != null)
{
right = initPointer(start.X + 1, start.Y);
if (VisitedList.Exists(x => x.X == right.X && x.Y == right.Y))
{
right = null;
}
if (right != null)
{
BackUpList.Add(right);
}
current = GetShorter(current, right);
}
}
foreach (var backup in BackUpList)
{
current = GetShorter(current, backup);
}
AStar(current, end);
}