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justcoding121justcoding121
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generic support on weighted digraph adjacency matrix graph
1 parent 2963d19 commit 8cbb7bb

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9 files changed

+646
-54
lines changed

9 files changed

+646
-54
lines changed

‎src/Advanced.Algorithms/DataStructures/Graph/AdjacencyMatrix/WeightedDiGraph.cs‎

Lines changed: 205 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -9,25 +9,49 @@ namespace Advanced.Algorithms.DataStructures.Graph.AdjacencyMatrix
99
/// A weighted graph implementation using dynamically growinng/shrinking adjacency matrix array.
1010
/// IEnumerable enumerates all vertices.
1111
/// </summary>
12-
public class WeightedDiGraph<T, TW> : IEnumerable<T> where TW : IComparable
12+
public class WeightedDiGraph<T, TW> : IDiGraph<T>, IGraph<T>, IEnumerable<T> where TW : IComparable
1313
{
14-
public int VerticesCount => usedSize;
14+
public int VerticesCount { get; private set; }
1515

1616
private Dictionary<T, int> vertexIndices;
1717
private Dictionary<int, T> reverseVertexIndices;
18+
private Dictionary<T, WeightedDiGraphVertex<T, TW>> vertexObjects;
1819

1920
private TW[,] matrix;
21+
private int maxSize => matrix.GetLength(0);
22+
23+
public bool IsWeightedGraph => true;
2024

21-
private int maxSize;
22-
private int usedSize;
2325
private int nextAvailableIndex;
2426

2527
public WeightedDiGraph()
2628
{
27-
maxSize = 1;
2829
vertexIndices = new Dictionary<T, int>();
2930
reverseVertexIndices = new Dictionary<int, T>();
30-
matrix = new TW[maxSize, maxSize];
31+
vertexObjects = new Dictionary<T, WeightedDiGraphVertex<T, TW>>();
32+
33+
matrix = new TW[1, 1];
34+
}
35+
36+
public IDiGraphVertex<T> ReferenceVertex => getReferenceVertex();
37+
IGraphVertex<T> IGraph<T>.ReferenceVertex => getReferenceVertex();
38+
39+
private WeightedDiGraphVertex<T, TW> getReferenceVertex()
40+
{
41+
if (this.VerticesCount == 0)
42+
{
43+
throw new Exception("Empty graph.");
44+
}
45+
46+
return vertexObjects[this.First()];
47+
}
48+
49+
public IEnumerable<IDiGraphVertex<T>> VerticesAsEnumberable => getVerticesAsEnumerable();
50+
IEnumerable<IGraphVertex<T>> IGraph<T>.VerticesAsEnumberable => getVerticesAsEnumerable();
51+
52+
private IEnumerable<WeightedDiGraphVertex<T, TW>> getVerticesAsEnumerable()
53+
{
54+
return this.Select(x => vertexObjects[x]);
3155
}
3256

3357
/// <summary>
@@ -46,7 +70,7 @@ public void AddVertex(T value)
4670
throw new Exception("Vertex exists.");
4771
}
4872

49-
if (usedSize < maxSize / 2)
73+
if (VerticesCount < maxSize / 2)
5074
{
5175
halfMatrixSize();
5276
}
@@ -58,8 +82,9 @@ public void AddVertex(T value)
5882

5983
vertexIndices.Add(value, nextAvailableIndex);
6084
reverseVertexIndices.Add(nextAvailableIndex, value);
85+
vertexObjects.Add(value, new WeightedDiGraphVertex<T, TW>(this, value));
6186
nextAvailableIndex++;
62-
usedSize++;
87+
VerticesCount++;
6388

6489
}
6590

@@ -79,13 +104,13 @@ public void RemoveVertex(T value)
79104
throw new Exception("Vertex does'nt exist.");
80105
}
81106

82-
if (usedSize <= maxSize / 2)
107+
if (VerticesCount <= maxSize / 2)
83108
{
84109
halfMatrixSize();
85110
}
86111

87112
var index = vertexIndices[value];
88-
113+
89114
//clear edges
90115
for (int i = 0; i < maxSize; i++)
91116
{
@@ -95,8 +120,8 @@ public void RemoveVertex(T value)
95120

96121
reverseVertexIndices.Remove(index);
97122
vertexIndices.Remove(value);
98-
99-
usedSize--;
123+
vertexObjects.Remove(value);
124+
VerticesCount--;
100125

101126
}
102127

@@ -184,7 +209,7 @@ public bool HasEdge(T source, T dest)
184209
return false;
185210
}
186211

187-
public IEnumerable<Tuple<T, TW>> OutEdges(T vertex)
212+
public int OutEdgeCount(T vertex)
188213
{
189214
if (!vertexIndices.ContainsKey(vertex))
190215
{
@@ -193,20 +218,20 @@ public IEnumerable<Tuple<T, TW>> OutEdges(T vertex)
193218

194219
var index = vertexIndices[vertex];
195220

196-
var result = new List<Tuple<T, TW>>();
221+
int count = 0;
197222

198223
for (int i = 0; i < maxSize; i++)
199224
{
200-
if (!matrix[index,i].Equals(default(TW)))
225+
if (!matrix[index, i].Equals(default(TW)))
201226
{
202-
result.Add(new Tuple<T,TW>(reverseVertexIndices[i], matrix[index, i]));
227+
count++;
203228
}
204229
}
205230

206-
return result;
231+
return count;
207232
}
208233

209-
public IEnumerable<Tuple<T, TW>> InEdges(T vertex)
234+
public IEnumerable<KeyValuePair<T, TW>> OutEdges(T vertex)
210235
{
211236
if (!vertexIndices.ContainsKey(vertex))
212237
{
@@ -217,15 +242,55 @@ public IEnumerable<Tuple<T, TW>> InEdges(T vertex)
217242

218243
var result = new List<Tuple<T, TW>>();
219244

245+
for (int i = 0; i < maxSize; i++)
246+
{
247+
if (!matrix[index, i].Equals(default(TW)))
248+
{
249+
yield return new KeyValuePair<T, TW>(reverseVertexIndices[i], matrix[index, i]);
250+
}
251+
}
252+
}
253+
254+
public int InEdgeCount(T vertex)
255+
{
256+
if (!vertexIndices.ContainsKey(vertex))
257+
{
258+
throw new ArgumentException("vertex is not in this graph.");
259+
}
260+
261+
var index = vertexIndices[vertex];
262+
263+
int count = 0;
264+
220265
for (int i = 0; i < maxSize; i++)
221266
{
222267
if (!matrix[i, index].Equals(default(TW)))
223268
{
224-
result.Add(new Tuple<T, TW>(reverseVertexIndices[i], matrix[i, index]));
269+
count++;
225270
}
226271
}
227272

228-
return result;
273+
return count;
274+
}
275+
276+
public IEnumerable<KeyValuePair<T, TW>> InEdges(T vertex)
277+
{
278+
if (!vertexIndices.ContainsKey(vertex))
279+
{
280+
throw new ArgumentException("vertex is not in this graph.");
281+
}
282+
283+
var index = vertexIndices[vertex];
284+
285+
var result = new List<Tuple<T, TW>>();
286+
287+
for (int i = 0; i < maxSize; i++)
288+
{
289+
if (!matrix[i, index].Equals(default(TW)))
290+
{
291+
yield return new KeyValuePair<T, TW>(reverseVertexIndices[i], matrix[i, index]);
292+
}
293+
}
229294
}
230295

231296
private void doubleMatrixSize()
@@ -248,7 +313,7 @@ private void doubleMatrixSize()
248313
{
249314
for (int j = 0; j < maxSize; j++)
250315
{
251-
if (!matrix[i, j].Equals(default(TW))
316+
if (!matrix[i, j].Equals(default(TW))
252317
&& reverseVertexIndices.ContainsKey(i)
253318
&& reverseVertexIndices.ContainsKey(j))
254319
{
@@ -263,7 +328,7 @@ private void doubleMatrixSize()
263328
matrix = newMatrix;
264329
vertexIndices = newVertexIndices;
265330
reverseVertexIndices = newReverseIndices;
266-
maxSize *= 2;
331+
267332
}
268333

269334
private void halfMatrixSize()
@@ -286,7 +351,7 @@ private void halfMatrixSize()
286351
{
287352
for (int j = 0; j < maxSize; j++)
288353
{
289-
if (!matrix[i, j].Equals(default(TW))
354+
if (!matrix[i, j].Equals(default(TW))
290355
&& reverseVertexIndices.ContainsKey(i)
291356
&& reverseVertexIndices.ContainsKey(j))
292357
{
@@ -301,7 +366,6 @@ private void halfMatrixSize()
301366
matrix = newMatrix;
302367
vertexIndices = newVertexIndices;
303368
reverseVertexIndices = newReverseIndices;
304-
maxSize /= 2;
305369
}
306370

307371
IEnumerator IEnumerable.GetEnumerator()
@@ -313,5 +377,122 @@ public IEnumerator<T> GetEnumerator()
313377
{
314378
return vertexIndices.Select(x => x.Key).GetEnumerator();
315379
}
380+
381+
public bool ContainsVertex(T value)
382+
{
383+
return vertexIndices.ContainsKey(value);
384+
}
385+
386+
public IDiGraphVertex<T> GetVertex(T key)
387+
{
388+
return vertexObjects[key];
389+
}
390+
391+
IGraphVertex<T> IGraph<T>.GetVertex(T key)
392+
{
393+
return vertexObjects[key];
394+
}
395+
396+
IDiGraph<T> IDiGraph<T>.Clone()
397+
{
398+
return Clone();
399+
}
400+
401+
IGraph<T> IGraph<T>.Clone()
402+
{
403+
return Clone();
404+
}
405+
406+
public WeightedDiGraph<T, TW> Clone()
407+
{
408+
var graph = new WeightedDiGraph<T, TW>();
409+
410+
foreach (var vertex in this)
411+
{
412+
graph.AddVertex(vertex);
413+
}
414+
415+
foreach (var vertex in this)
416+
{
417+
foreach (var edge in OutEdges(vertex))
418+
{
419+
graph.AddEdge(vertex, edge.Key, edge.Value);
420+
}
421+
}
422+
423+
return graph;
424+
}
425+
426+
/// <summary>
427+
/// IEnumerable enumerates all the outgoing edge destination vertices.
428+
/// </summary>
429+
private class WeightedDiGraphVertex<T, TW> : IDiGraphVertex<T>, IGraphVertex<T> where TW : IComparable
430+
{
431+
WeightedDiGraph<T, TW> graph;
432+
private int vertexIndex;
433+
private T vertexKey;
434+
435+
private int maxSize => graph.maxSize;
436+
private TW[,] matrix => graph.matrix;
437+
438+
private Dictionary<T, int> vertexIndices => graph.vertexIndices;
439+
private Dictionary<int, T> reverseVertexIndices => graph.reverseVertexIndices;
440+
441+
internal WeightedDiGraphVertex(WeightedDiGraph<T, TW> graph, T vertexKey)
442+
{
443+
if (!graph.vertexIndices.ContainsKey(vertexKey))
444+
{
445+
throw new ArgumentException("vertex is not in this graph.");
446+
}
447+
448+
this.graph = graph;
449+
this.vertexKey = vertexKey;
450+
this.vertexIndex = graph.vertexIndices[vertexKey];
451+
}
452+
453+
public T Key => vertexKey;
454+
455+
IEnumerable<IDiEdge<T>> IDiGraphVertex<T>.OutEdges => OutEdges()
456+
.Select(x => new DiEdge<T, TW>(graph.vertexObjects[x.Key], x.Value));
457+
458+
IEnumerable<IDiEdge<T>> IDiGraphVertex<T>.InEdges => InEdges()
459+
.Select(x => new DiEdge<T, TW>(graph.vertexObjects[x.Key], x.Value));
460+
461+
IEnumerable<IEdge<T>> IGraphVertex<T>.Edges => OutEdges()
462+
.Select(x => new Edge<T, TW>(graph.vertexObjects[x.Key], x.Value));
463+
464+
public int OutEdgeCount => graph.OutEdgeCount(vertexKey);
465+
public int InEdgeCount => graph.InEdgeCount(vertexKey);
466+
467+
public IEnumerable<KeyValuePair<T, TW>> OutEdges() => graph.OutEdges(vertexKey);
468+
public IEnumerable<KeyValuePair<T, TW>> InEdges() => graph.InEdges(vertexKey);
469+
470+
public IDiEdge<T> GetOutEdge(IDiGraphVertex<T> targetVertex)
471+
{
472+
if (!vertexIndices.ContainsKey(targetVertex.Key))
473+
{
474+
throw new ArgumentException("vertex is not in this graph.");
475+
}
476+
477+
var index = vertexIndices[targetVertex.Key];
478+
var key = targetVertex as WeightedDiGraphVertex<T, TW>;
479+
return new DiEdge<T, TW>(targetVertex, matrix[vertexIndex, index]);
480+
}
481+
482+
public IEdge<T> GetEdge(IGraphVertex<T> targetVertex)
483+
{
484+
if (!vertexIndices.ContainsKey(targetVertex.Key))
485+
{
486+
throw new ArgumentException("vertex is not in this graph.");
487+
}
488+
489+
var index = vertexIndices[targetVertex.Key];
490+
var key = targetVertex as WeightedDiGraphVertex<T, TW>;
491+
return new Edge<T, TW>(targetVertex, matrix[vertexIndex, index]);
492+
}
493+
494+
}
316495
}
496+
497+
317498
}

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