/// <summary>
/// 计算从点s到其他所有点的路径
/// </summary>
/// <param name="s"></param>
/// <returns></returns>
public List <int> CalculatePath(int s)
{
List <bool> visited = new List <bool>(polys.Count);
List <float> length = new List <float>(polys.Count);
List <int> from = new List <int>(polys.Count);
for (int i = 0; i < polys.Count; i++)
{
visited.Add(false);
length.Add(Single.MaxValue);
from.Add(-1);
}
RBTree <float, int> queue = new RBTree <float, int>();
visited[s] = true;
length[s] = 0f;
queue.Add(0f, s);
while (queue.Count > 0)
{
KeyValuePair <float, int> vPair = queue.Min();
int v = vPair.Value;
queue.Remove(vPair.Key);
//每次拿出来的最小值一定属于最短路径(贪心性质)
visited[v] = true;
if (NearPolys.ContainsKey(v))
{
foreach (PolyConnection e in nearPolys[v])
{
int w = e.Other(v);
if (!visited[w])
{
float l = length[v] + e.Weight;
if (from[w] == -1 || l < length[w])
{
length[w] = l;
from[w] = v;
if (queue.ContainsValue(w))
{//这里用sortedList的更新操作(删除再插入)来实现优先队列的更新
queue.Remove(queue.KeyOfValue(w));
queue.Add(l, w);
}
else
{
queue.Add(l, w);
}
}
}
}
}
}
return(from);
}