public void TestAddED_RemoveED_5()
{
SimpleGraph graph = new SimpleGraph(3);
graph.AddVertex(1);
graph.AddVertex(2);
graph.AddVertex(3);
graph.AddEdge(0, 1);
graph.AddEdge(0, 2);
Assert.IsTrue(graph.m_adjacency[0, 1] == 1);
Assert.IsTrue(graph.m_adjacency[0, 2] == 1);
graph.RemoveEdge(0, 2);
Assert.IsTrue(graph.m_adjacency[0, 1] == 1);
Assert.IsTrue(graph.m_adjacency[0, 2] == 0);
graph.AddEdge(2, 0);
Assert.IsTrue(graph.m_adjacency[0, 1] == 1);
Assert.IsTrue(graph.m_adjacency[0, 2] == 1);
graph.RemoveEdge(2, 0);
Assert.IsTrue(graph.m_adjacency[0, 1] == 1);
Assert.IsTrue(graph.m_adjacency[2, 0] == 0);
}
// The only way to cover a leaf's edge is by choosing the leaf, or by choosing
// its parent. Choosing its parent is better since that'll cover other edges
// as well. This solution chooses leaf parents, and removes from the tree any
// edges the leaf parent covers. As this removal process happens, new leaves
// get created and set aside to work on. Once there are no more leaves left,
// we're done. We know this works because assume we missed part of the tree. The
// part is also a tree, so it has a leaf. This leaf wasn't one of the initial leaves,
// otherwise we would've seen it already. So to be a leaf now it must've had an
// edge removed, so it must've been a neighbor of one of the parent leaves,
// so we must've seen it, contradiction.
public static int Solve(SimpleGraph tree)
{
var leaves = new HashSet <Vertex>(tree.Vertices.Where(v => v.Degree == 1));
int vertexCoverSize = 0;
while (leaves.Any())
{
var leaf = leaves.First();
var parentLeaf = leaf.Neighbors.First();
var parentLeafNeighbors = parentLeaf.Neighbors.ToArray();
foreach (var parentLeafNeighor in parentLeafNeighbors)
{
tree.RemoveEdge(parentLeaf, parentLeafNeighor);
if (parentLeafNeighor.Degree == 1)
{
leaves.Add(parentLeafNeighor);
}
else if (parentLeafNeighor.Degree == 0)
{
leaves.Remove(parentLeafNeighor);
}
}
// Parent may have been a leaf, and its degree is 0 now, so try removing.
leaves.Remove(parentLeaf);
++vertexCoverSize;
}
return(vertexCoverSize);
}
public void TestRemoveEdge()
{
Assert.IsTrue(_graph.IsEdge(0, 3));
Assert.IsTrue(_graph.IsEdge(3, 0));
_graph.RemoveEdge(0, 3);
Assert.IsFalse(_graph.IsEdge(0, 3));
Assert.IsFalse(_graph.IsEdge(3, 0));
}
public void RemoveEdge()
{
var g = new SimpleGraph(4);
g.AddVertex(1);
g.AddVertex(2);
g.AddEdge(1, 2);
g.AddEdge(1, 1);
Assert.True(g.IsEdge(1, 2));
Assert.True(g.IsEdge(1, 1));
g.RemoveEdge(1, 2);
Assert.True(!g.IsEdge(1, 2));
Assert.True(g.IsEdge(1, 1));
g.RemoveEdge(1, 1);
Assert.True(!g.IsEdge(1, 2));
Assert.True(!g.IsEdge(1, 1));
g.RemoveEdge(3, 3);
}
public void removeEdge()
{
int[] arr = { 10, 15, 21, 23 };
foreach (int item in arr)
{
graph.AddVertex(item);
}
int[] j = { 0, 0, 1, 0, 2 };
int[] k = { 1, 2, 2, 3, 3 };
for (int i1 = 0; i1 < j.Length; i1++)
{
if (!graph.IsEdge(j[i1], k[i1]))
{
graph.AddEdge(j[i1], k[i1]);
if (!graph.IsEdge(j[i1], k[i1]))
{
Assert.Fail();
}
}
else
{
Assert.Fail();
}
}
if (!graph.IsEdge(0, 3))
{
Assert.Fail();
}
graph.RemoveEdge(0, 3);
if (graph.IsEdge(0, 3))
{
Assert.Fail();
}
}
public void TestAddED_RemoveED_4()
{
SimpleGraph graph = new SimpleGraph(7);
graph.AddVertex(1);
graph.AddVertex(2);
graph.AddVertex(3);
graph.AddVertex(4);
graph.AddVertex(5);
graph.AddVertex(6);
graph.AddVertex(7);
graph.AddEdge(0, 1);
graph.AddEdge(0, 2);
graph.AddEdge(0, 3);
graph.AddEdge(0, 4);
graph.AddEdge(0, 5);
graph.AddEdge(0, 6);
graph.AddEdge(3, 5);
Assert.IsTrue(graph.m_adjacency[0, 3] == 1);
Assert.IsTrue(graph.m_adjacency[0, 5] == 1);
Assert.IsTrue(graph.vertex[3] != null);
Assert.IsTrue(graph.vertex[5] != null);
graph.RemoveVertex(3);
Assert.IsTrue(graph.m_adjacency[0, 3] == 0);
Assert.IsTrue(graph.m_adjacency[0, 5] == 1);
Assert.IsTrue(graph.vertex[3] == null);
Assert.IsTrue(graph.vertex[5] != null);
graph.RemoveEdge(0, 5);
Assert.IsTrue(graph.m_adjacency[0, 5] == 0);
Assert.IsTrue(graph.vertex[5] != null);
graph.AddEdge(5, 0);
Assert.IsTrue(graph.m_adjacency[0, 5] == 1);
Assert.IsTrue(graph.vertex[5] != null);
}
public void RemoveEdge_5e_in_5v_Graph()
{
int size = 5;
SimpleGraph <int> testGraph = new SimpleGraph <int>(size);
testGraph.AddVertex(19);
testGraph.AddVertex(18);
testGraph.AddVertex(17);
testGraph.AddVertex(16);
testGraph.AddVertex(15);
Assert.IsTrue(testGraph.vertex[0].Value == 19);
Assert.IsTrue(testGraph.vertex[1].Value == 18);
Assert.IsTrue(testGraph.vertex[2].Value == 17);
Assert.IsTrue(testGraph.vertex[3].Value == 16);
Assert.IsTrue(testGraph.vertex[4].Value == 15);
Assert.AreEqual(size, testGraph.max_vertex);
Assert.AreEqual(size, testGraph.vertex.Length);
Assert.AreEqual(size, testGraph.m_adjacency.GetLength(0));
Assert.AreEqual(size, testGraph.m_adjacency.GetLength(1));
Assert.AreEqual(0, testGraph.m_adjacency[0, 2]);
Assert.AreEqual(0, testGraph.m_adjacency[2, 0]);
testGraph.AddEdge(0, 1); // добавление ребра между вершинами
testGraph.AddEdge(0, 2);
testGraph.AddEdge(0, 3);
testGraph.AddEdge(2, 1);
testGraph.AddEdge(2, 3);
Assert.IsTrue(testGraph.IsEdge(0, 1)); // проверка добавления ребёр
Assert.IsTrue(testGraph.IsEdge(0, 2));
Assert.IsTrue(testGraph.IsEdge(0, 3));
Assert.IsTrue(testGraph.IsEdge(2, 1));
Assert.IsTrue(testGraph.IsEdge(2, 3));
for (int i = 0; i < testGraph.m_adjacency.GetLength(0); i++)
{
for (int j = 0; j < testGraph.m_adjacency.GetLength(1); j++)
{
Console.Write(testGraph.m_adjacency[i, j] + " ");
}
Console.WriteLine();
}
Assert.AreEqual(1, testGraph.m_adjacency[0, 1]);
Assert.AreEqual(1, testGraph.m_adjacency[0, 2]);
Assert.AreEqual(1, testGraph.m_adjacency[0, 3]);
Assert.AreEqual(1, testGraph.m_adjacency[1, 0]);
Assert.AreEqual(1, testGraph.m_adjacency[1, 2]);
Assert.AreEqual(1, testGraph.m_adjacency[2, 0]);
Assert.AreEqual(1, testGraph.m_adjacency[2, 1]);
Assert.AreEqual(1, testGraph.m_adjacency[2, 3]);
Assert.AreEqual(1, testGraph.m_adjacency[3, 0]);
Assert.AreEqual(1, testGraph.m_adjacency[3, 2]);
testGraph.RemoveEdge(0, 1); // удаление ребер между вершинами
testGraph.RemoveEdge(0, 2);
testGraph.RemoveEdge(0, 3);
testGraph.RemoveEdge(2, 1);
testGraph.RemoveEdge(2, 3);
for (int i = 0; i < testGraph.m_adjacency.GetLength(0); i++)
{
for (int j = 0; j < testGraph.m_adjacency.GetLength(1); j++)
{
Console.Write(testGraph.m_adjacency[i, j] + " ");
}
Console.WriteLine();
}
}
