public void Test()
{
var pq = new IndexMinPQ <int>(10);
pq.Enqueue(1, 20);
pq.Enqueue(2, 15);
Assert.Equal(15, pq.MinKey());
pq.Enqueue(1, 10);
Assert.Equal(10, pq.MinKey());
pq.Enqueue(3, 11);
Assert.Equal(1, pq.DelMin());
Assert.Equal(11, pq.MinKey());
Assert.Equal(2, pq.Count);
Assert.False(pq.IsEmpty);
pq.Enqueue(2, 10);
Assert.Equal(10, pq.MinKey());
Assert.Equal(2, pq.DelMin());
foreach (var v in pq)
{
console.WriteLine("key: {0}", v);
}
}
/// <summary>
/// Demo test the <c>IndexMinPQ</c> data type.</summary>
/// <param name="args">Place holder for user arguments</param>
///
public static void MainTest(string[] args)
{
// insert a bunch of strings
string[] strings =
{
"it",
"was",
"the",
"best",
"of",
"times",
"it",
"was",
"the",
"worst"
};
IndexMinPQ <string> pq = new IndexMinPQ <string>(strings.Length);
for (int i = 0; i < strings.Length; i++)
{
pq.Insert(i, strings[i]);
}
// delete and print each key
while (!pq.IsEmpty)
{
int i = pq.DelMin();
Console.WriteLine(i + " " + strings[i]);
}
Console.WriteLine();
// reinsert the same strings
for (int i = 0; i < strings.Length; i++)
{
pq.Insert(i, strings[i]);
}
// print each key using the iterator
foreach (int i in pq)
{
Console.WriteLine(i + " " + strings[i]);
}
while (!pq.IsEmpty)
{
Console.WriteLine("Min k={0} at {1}", pq.MinKey, pq.MinIndex);
Console.WriteLine("Removed {0}", pq.DelMin());
}
}
public void IndexMinPQTest1()
{
const int MaxSize = 8;
const double MinValue = 3.9;
const double MaxValue = MinValue * MaxSize + 32;
int index;
// MinValue index == 3, MaxValue index == 4
double[] items = { MinValue * 2, MinValue * 3, MinValue * 4, MinValue, MaxValue, MinValue * 5, MinValue * 6, MinValue * 7 };
StdRandom.Seed = 101;
IndexMinPQ <double> pq = new IndexMinPQ <double>(MaxSize);
index = StdRandom.Uniform(items.Length);
Assert.IsFalse(pq.Contains(index));
Assert.IsTrue(pq.IsEmpty);
Assert.AreEqual(0, pq.Count);
try
{
index = pq.DelMin();
Assert.Fail("Failed to catch exception");
}
catch (InvalidOperationException) { }
for (int i = 0; i < items.Length; i++)
{
pq.Insert(i, items[i]);
}
Assert.AreEqual(items.Length, pq.Count);
Assert.AreEqual(MinValue, pq.MinKey);
Assert.AreEqual(3, pq.MinIndex);
Assert.AreEqual(MaxValue, pq.KeyOf(4));
index = StdRandom.Uniform(items.Length);
Assert.AreEqual(items[index], pq.KeyOf(index));
pq.ChangeKey(1, pq.MinKey * 0.9); // make it the smallest item
Assert.AreEqual(1, pq.MinIndex);
pq.DecreaseKey(3, pq.MinKey * 0.87);
Assert.AreEqual(3, pq.MinIndex);
pq.Delete(3);
Assert.AreNotEqual(3, pq.MinIndex);
Assert.AreEqual(1, pq.DelMin());
}
public Dijkstra(WeightedDiGraph G, int s)
{
this.s = s;
int V = G.V();
marked = new bool[V];
edgeTo = new Edge[V];
cost = new double[V];
for (var i = 0; i < V; ++i)
{
cost[i] = Double.MaxValue;
}
cost[s] = 0;
pq = new IndexMinPQ <Double>(V);
pq.Insert(s, 0);
while (!pq.IsEmpty)
{
var v = pq.DelMin();
marked[v] = true;
foreach (var e in G.adj(v))
{
Relax(G, e);
}
}
}
private readonly IndexMinPQ <Double> _pq; // priority queue of vertices
/// <summary>
/// Computes a shortest-paths tree from the source vertex <tt>s</tt> to every other
/// vertex in the edge-weighted digraph <tt>G</tt>.
/// </summary>
/// <param name="g">g the edge-weighted digraph</param>
/// <param name="s">s the source vertex</param>
/// <exception cref="ArgumentException">if an edge weight is negative</exception>
/// <exception cref="ArgumentException">unless 0 <= <tt>s</tt> <= <tt>V</tt> - 1</exception>
public DijkstraSP(EdgeWeightedDigraph g, int s)
{
foreach (var e in g.Edges())
{
if (e.Weight < 0)
{
throw new ArgumentException($"edge {e} has negative weight");
}
}
_distTo = new double[g.V];
_edgeTo = new DirectedEdge[g.V];
for (var v = 0; v < g.V; v++)
{
_distTo[v] = double.PositiveInfinity;
}
_distTo[s] = 0.0;
// relax vertices in order of distance from s
_pq = new IndexMinPQ <Double>(g.V);
_pq.Insert(s, _distTo[s]);
while (!_pq.IsEmpty())
{
var v = _pq.DelMin();
foreach (var e in g.Adj(v))
{
Relax(e);
}
}
// check optimality conditions
//assert check(G, s);
}
public LazyPrimMinSpanningTree(EdgeWeightedGraph g)
{
pq = new IndexMinPQ <Edge>(g.EdgeCount);
marked = new bool[g.VertexCount];
mst = new Queue <Edge>();
Visit(g, 0);
while (!pq.IsEmpty())
{
Edge e = pq.DelMin();
int v1 = e.CurrentValue;
int v2 = e.Other(v1);
if (marked[v1] && marked[v2])
{
continue;
}
mst.Enqueue(e);
if (marked[v1])
{
Visit(g, v1);
}
if (!marked[v2])
{
Visit(g, v2);
}
}
}
public DijkstraSP(EdgeWeightedDigraph g, int s)
{
foreach (DirectedEdge e in g.Edges())
{
if (e.Weight() < 0)
{
throw new ArgumentOutOfRangeException("graph edge must have nonegative weights");
}
}
distTo = new double[g.V];
edgeTo = new DirectedEdge[g.V];
for (int v = 0; v < g.V; v++)
{
distTo[v] = double.PositiveInfinity;
}
distTo[s] = 0;
//relax vertices in order of distance from s
pq = new IndexMinPQ <double>(g.V);
pq.Insert(s, distTo[s]);
while (!pq.IsEmpty())
{
int v = pq.DelMin();
foreach (DirectedEdge e in g.Adj(v))
{
relax(e);
}
}
}
private readonly IndexMinPQ<Double> _pq; // priority queue of vertices
#endregion Fields
#region Constructors
/// <summary>
/// Computes a shortest-paths tree from the source vertex <tt>s</tt> to every
/// other vertex in the edge-weighted graph <tt>G</tt>.
/// </summary>
/// <param name="g">g the edge-weighted graph</param>
/// <param name="s">s the source vertex</param>
/// <exception cref="ArgumentException">if an edge weight is negative</exception>
/// <exception cref="ArgumentException">unless 0 <= <tt>s</tt> <= <tt>V</tt> - 1</exception>
public DijkstraUndirectedSP(EdgeWeightedGraph g, int s)
{
foreach (var e in g.Edges())
{
if (e.Weight < 0)
throw new ArgumentException($"edge {e} has negative weight");
}
_distTo = new double[g.V];
_edgeTo = new EdgeW[g.V];
for (var v = 0; v < g.V; v++)
_distTo[v] = double.PositiveInfinity;
_distTo[s] = 0.0;
// relax vertices in order of distance from s
_pq = new IndexMinPQ<Double>(g.V);
_pq.Insert(s, _distTo[s]);
while (!_pq.IsEmpty())
{
var v = _pq.DelMin();
foreach (var e in g.Adj(v))
Relax(e, v);
}
// check optimality conditions
//assert check(G, s);
}
/// <summary>
/// run Prim's algorithm in graph G, starting from vertex s
/// </summary>
/// <param name="g"></param>
/// <param name="s"></param>
private void Prim(EdgeWeightedGraph g, int s)
{
_distTo[s] = 0.0;
_pq.Insert(s, _distTo[s]);
while (!_pq.IsEmpty())
{
var v = _pq.DelMin();
Scan(g, v);
}
}
private void prim(EdgeWeightedGraph g, int s)
{
distTo[s] = 0.0;
pq.Insert(s, distTo[s]);
while (!pq.IsEmpty())
{
int v = pq.DelMin();
scan(g, v);
}
}
public DifkstraSP(EdgeWeightedDigraph g, int s)
{
_edgeTo = new DirectedEdge[g.V];
_distTo = Enumerable.Repeat(double.PositiveInfinity, g.V).ToArray();
_pq = new IndexMinPQ <double>(g.V);
_distTo[s] = 0.0;
_pq.Insert(s, 0.0);
while (!_pq.IsEmpty())
{
Relax(g, _pq.DelMin());
}
}
public DijkstraAlgorithm(EdgeWeightedDigraph digraph, int source) : base(digraph, source)
{
//pq maintain a set of vertex need to deal with.
IndexMinPQ <double> pq = new IndexMinPQ <double>(digraph.V);
pq.Insert(source, distTo[source]);
while (!pq.IsEmpty())
{
//when v pops up, the distance and path to v have been confirmed
int v = pq.DelMin();
foreach (DirectedEdge e in digraph.Adj(v))
{
Relax(pq, e);
}
}
}
void IndexMinPQTest()
{
var strArr = FileHandler.ReadFileAsStrArr("words3.txt");
strArr.Show();
var pq = new IndexMinPQ <string>(strArr.Length);
for (int i = 0; i < strArr.Length; i++)
{
pq.Insert(i, strArr[i]);
}
while (!pq.IsEmpty())
{
Console.WriteLine(pq.DelMin());
}
Console.WriteLine();
Console.ReadKey();
}
private readonly decimal[] _distTo; // distTo[v] = distance of shortest s->v path
#endregion Fields
#region Constructors
/**
* Computes a shortest paths tree from <tt>s</tt> to every other vertex in
* the edge-weighted digraph <tt>G</tt>.
* @param G the edge-weighted digraph
* @param s the source vertex
* @throws IllegalArgumentException if an edge weight is negative
* @throws IllegalArgumentException unless 0 ≤ <tt>s</tt> ≤ <tt>V</tt> - 1
*/
public ShortestNeuronPath(NeuronGraph G, int s)
{
_distTo = new decimal[G.V()];
edgeTo = new DirectedEdge[G.V()];
for (int v = 0; v < G.V(); v++)
_distTo[v] = decimal.MaxValue;
_distTo[s] = 0.0M;
// relax vertices in order of distance from s
pq = new IndexMinPQ<decimal>(G.V());
pq.Insert(s, _distTo[s]);
while (!pq.IsEmpty())
{
int v = pq.DelMin();
foreach (DirectedEdge e in G.adj(v))
relax(e);
}
}
public void IndexMinPQ_Dequeue()
{
var q = new IndexMinPQ<int>(items.Length);
for (int i = 0; i < items.Length; i++)
{
q.Insert(i, items[i]);
}
var sortedItems = new List<int>(items);
sortedItems.Sort();
foreach (var item in sortedItems)
{
// The top of the queue returns the items in sorted order
var minIndex = q.DelMin();
Assert.AreEqual(items[minIndex], item);
}
}
public DijkstraSP(EdgeWeightedDigraph graph, int startVertex)
{
edgeTo = new DirectedEdge[graph.Vertices];
distTo = new double[graph.Vertices];
priorityQueue = new IndexMinPQ <double>(graph.Vertices);
for (int v = 0; v < graph.Vertices; v++)
{
distTo[v] = double.MaxValue;
}
distTo[startVertex] = 0.0f;
priorityQueue.Insert(startVertex, 0.0f);
while (!priorityQueue.IsEmpty())
{
Relax(graph, priorityQueue.DelMin());
}
}
public KruskalMinSpanningTree(EdgeWeightedGraph g)
{
mst = new Queue <Edge>();
IndexMinPQ <Edge> pq = new IndexMinPQ <Edge>(g.EdgeCount);
UnionFind_1 uf = new UnionFind_1(g.VertexCount);
while (!pq.IsEmpty() && mst.Count < g.VertexCount - 1)
{
Edge e = pq.DelMin();
int v1 = e.V1;
int v2 = e.Other(v1);
if (uf.Connected(v1, v2))
{
continue;
}
uf.Union(v1, v2);
mst.Enqueue(e);
}
}
public void DifkstraSPMy(EdgeWeightedDigraph g, int s)
{
_edgeTo = new DirectedEdge[g.V];
_distTo = Enumerable.Repeat(double.PositiveInfinity, g.V).ToArray();
_distTo[s] = 0.0;
_pq = new IndexMinPQ <double>(g.V);
foreach (var e in g.Adj(s))
{
_edgeTo[e.To] = e;
_distTo[e.To] = e.Weight;
_pq.Insert(e.To, e.Weight);
}
while (!_pq.IsEmpty())
{
var i = _pq.DelMin();
foreach (var e in g.Adj(i))
{
RelaxMy(i, e);
}
}
}
public DijkstraSP(EdgeWeightedDiagraph g, int source)
{
vertexNumber = g.V();
distTo = new double[vertexNumber];
for (int i = 0; i < vertexNumber; i++)
{
distTo[i] = double.PositiveInfinity;
}
distTo[source] = 0.0;
edgeTo = new DirectedEdge[vertexNumber];
pq = new IndexMinPQ <double>(vertexNumber);
pq.Insert(source, 0.0);
while (!pq.IsEmpty())
{
int current = pq.DelMin();
Relax(g, current);
}
}
public PrimMst(EdgeWeightedGraph graph)
{
edgeTo = new Edge[graph.Vertices];
distTo = new double[graph.Vertices];
marked = new bool[graph.Vertices];
for (int vertex = 0; vertex < graph.Vertices; vertex++)
{
distTo[vertex] = double.MaxValue;
}
prioryQueue = new IndexMinPQ <double>(graph.Vertices);
distTo[0] = 0.0f;
prioryQueue.Insert(0, 0.0f);
while (!prioryQueue.IsEmpty())
{
Visit(graph, prioryQueue.DelMin());
}
}
//ctor inits DSs, builds shortest path tree and computes distances
//takes a built DiGraph and a source vertex
public DijkstrasShortestPath(EdgeWeightedDiGraph g, int s)
{
_pq = new IndexMinPQ <double>(g.V);
_edgeTo = new DirectedEdge[g.V];
_distTo = new double[g.V];
//load initial values
for (int i = 1; i < g.V; i++)
{
_distTo[i] = Double.PositiveInfinity;
}
_distTo[s] = 0.0;
_edgeTo[s] = null;
//loads a starting value onto PQ to start process
_pq.Insert(s, _distTo[s]);
//start business logic
//start cycle of deleting min edges and checking adj edges for 'eligability'
while (!_pq.IsEmpty())
{
var minV = _pq.DelMin();
Relax(g, minV);
}
}
public EagerPrim(WeightedGraph G)
{
int V = G.V();
pq = new IndexMinPQ <Edge>(V);
marked = new bool[V];
Visit(G, 0);
path = new List <Edge>();
while (!pq.IsEmpty)
{
var e = pq.MinKey();
var v = pq.DelMin();
path.Add(e);
if (!marked[v])
{
Visit(G, v);
}
}
}
// Returns shortest path from src to dst (not including src)
public List <TileNode> GetShortestPath(Vector2Int src, Vector2Int dst, UnitType unitType)
{
float[,] distance = new float[width, height];
Vector2Int[,] prev = new Vector2Int[width, height];
IndexMinPQ <float> minPQ = new IndexMinPQ <float>(width * height);
distance[src.x, src.y] = 0.0f;
prev[src.x, src.y] = src;
minPQ.Insert(ToTileIndex1D(src), 0.0f);
for (int i = 0; i < width; i++)
{
for (int j = 0; j < height; j++)
{
if (i == src.x && j == src.y)
{
continue;
}
distance[i, j] = float.PositiveInfinity;
prev[i, j] = new Vector2Int(-1, -1);
minPQ.Insert(ToTileIndex1D(i, j), float.PositiveInfinity);
}
}
while (!minPQ.IsEmpty)
{
float dist = minPQ.MinKey;
Vector2Int min = ToTileIndex2D(minPQ.DelMin());
Vector2Int[] neighbors = GetNeighbors(min);
foreach (Vector2Int neighbor in neighbors)
{
int neighborInd = ToTileIndex1D(neighbor);
float edgeDist = GetTileMoveWeight(neighbor, unitType);
if (minPQ.Contains(neighborInd) && edgeDist != 0.0f)
{
float currentDist = minPQ.KeyOf(neighborInd);
if (dist + edgeDist < currentDist)
{
distance[neighbor.x, neighbor.y] = dist + edgeDist;
prev[neighbor.x, neighbor.y] = min;
minPQ.DecreaseKey(neighborInd, dist + edgeDist);
}
}
}
}
if (distance[dst.x, dst.y] == float.PositiveInfinity)
{
return(null);
}
List <TileNode> path = new List <TileNode>();
TileNode dstNode;
dstNode.coords = dst;
dstNode.dist = distance[dst.x, dst.y];
path.Add(dstNode);
Vector2Int tile = dst;
while (prev[tile.x, tile.y] != src)
{
tile = prev[tile.x, tile.y];
TileNode node;
node.coords = tile;
node.dist = distance[tile.x, tile.y];
path.Add(node);
}
path.Reverse();
return(path);
}
