public Dijkstra(WeightSpareGraph <float> graph, int src)
{
Debug.Assert(src >= 0 && src < graph.V());
this.src = src;
this.graph = graph;
this.n = graph.V();
this.m = graph.E();
shortPath = new float[n];
book = new bool[n];
from = new int[n];
for (int i = 0; i != n; i++)
{
book [i] = false;
from [i] = -1; //假设都是可达的
}
from [src] = -1;
shortPath [src] = 0f;
IndexMinHeap <float> indexMinHeap = new IndexMinHeap <float> (n);
indexMinHeap.Insert(src, shortPath[src]);
while (indexMinHeap.Size() != 0)
{
int u = indexMinHeap.ExtraMinItemIndex();
book [u] = true;
WeightSpareGraph <float> .adjIterator iter = new WeightSpareGraph <float> .adjIterator(graph, u);
for (Edge <float> e = iter.begin(); !iter.isEnd(); e = iter.Next())
{
int v = e.Other(u);
if (!book[v])
{
if (from [v] == -1 || shortPath [v] > shortPath [u] + e.weight)
{
from [v] = u;
shortPath [v] = shortPath [u] + e.weight;
if (indexMinHeap.isContain(v))
{
indexMinHeap.Change(v, shortPath [v]);
}
else
{
indexMinHeap.Insert(v, shortPath[v]);
}
}
}
}
}
}
public PrimMST(WeightSpareGraph <float> graph)
{
this.graph = graph;
this.n = graph.V();
this.m = graph.E();
minSpanTreeValue = 0;
book = new bool[n];
toEdgeArr = new List <Edge <float> >();
for (int i = 0; i != n; i++)
{
toEdgeArr.Add(null);
}
for (int i = 0; i != n; i++)
{
book [i] = false;
}
indexMinHeap = new IndexMinHeap <float> (m);
book [0] = true;
visit(0);
while (indexMinHeap.Size() != 0)
{
int index = indexMinHeap.ExtraMinItemIndex();
Debug.Assert(toEdgeArr[index] != null);
book[index] = true;
visit(index);
// int u = toEdgeArr [index].U ();
// int v = toEdgeArr [index].V ();
// if (book [u] && !book [v]) {
// book [v] = true;
// visit (v);
// } else if(!book [u] && book [v]){
// book [u] = true;
// visit (u);
// }
}
for (int i = 1; i != n; i++)
{
minSpanTreeValue += toEdgeArr [i].weight;
}
}