public static Graph CreateEulerGraph(int nodes, out string finalEulerPath)
{
while (true)
{
Random rand = new Random();
int CounterOfConnections = 0;
int n = nodes;
double b = 0.5;
//tworze losowy graf o 10 wierzchołkach i stopniu 0.5
int[,] result = new int[n, n];
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
result[i, j] = 0;
}
}
for (int i = 1; i < n; i++)
{
for (int j = 0; j < i; j++)
{
if (rand.NextDouble() < b)
{
result[i, j] = 1;
result[j, i] = 1;
CounterOfConnections++;
}
}
}
//zmieniam graf aby był eulerowski
for (int i = 0; i < n - 1; i++)
{
int deg = 0;
for (int j = 0; j < n; j++)
{
if (result[i, j] > 0)
{
deg++;
}
}
//check if degree is even
if (deg % 2 != 0)
{
int x = rand.Next(n - i - 1) + i + 1;
if (result[i, x] > 0)
{
result[i, x] = 0;
result[x, i] = 0;
CounterOfConnections--;
}
else
{
result[i, x] = 1;
result[x, i] = 1;
CounterOfConnections++;
}
}
}
if (CounterOfConnections != 0)
{
Graph finalGraph = GraphCreator.CreateFromMatrix(result);
finalEulerPath = CreateEulerPath(result, n, CounterOfConnections, finalGraph);
return(finalGraph);
}
}
}
public static string CreateEulerPath(int[,] result, int n, int count, Graph eulersGraph)
{
int CounterOfConnections = count;
//wypisuje mój eulerowski graf
List <int> countOfNodes = new List <int>();
for (int i = 0; i < n; i++)
{
countOfNodes.Add(0);
for (int j = 0; j < n; j++)
{
if (result[i, j] == 1)
{
countOfNodes[i]++;
}
}
countOfNodes[i] /= 2;
}
//stos moich podcyklów
List <List <int> > StackOfLists = new List <List <int> >();
//indexy w tablicy sąsiedztwa
int x_index = 0, y_index = 0;
//CounterOfList mówi nam ile list mamy na stosie
int CounterOfLists = 0;
while (true)
{
if (CounterOfConnections == 0)
{
break;
}
//znczy to że przeleciałem cały graf już
StackOfLists.Add(new List <int>());
//szukam wierzchołka które jeszcze nie jest w żadnym podgrafie
//jeżeli nie ma jeszcze żadnego podgrafu to szukam pierwszego lepszego
if (CounterOfLists == 0)
{
for (int i = 0; i < n; i++)
{
if (countOfNodes[i] != 0)
{
x_index = i;
}
}
}
else
{
foreach (int element in StackOfLists[CounterOfLists - 1])
{
if (countOfNodes[element] != 0)
{
x_index = element;
}
}
}
//szukam ygrekowej składowej
for (int i = 0; i < n; i++)
{
if (result[x_index, i] == 1)
{
y_index = i;
}
}
//kończe szukanie tego wierzchołka
StackOfLists[CounterOfLists].Add(x_index);
while (true)
{
bool noChange = true;
StackOfLists[CounterOfLists].Add(y_index);
countOfNodes[x_index]--;
result[x_index, y_index] = 0;
result[y_index, x_index] = 0;
CounterOfConnections--;
//dodało nam wierzchołek do cyklu i teraz sprawdza czy czasem
//czasem nie trzeba rzucić nowej listy na stos
for (int i = 0; i < n; i++)
{
if (result[y_index, i] == 1)
{
x_index = y_index;
y_index = i;
noChange = false;
break;
}
}
if (noChange)
{
break;
}
}
CounterOfLists++;
}
//złoże teraz mój stos w finalną liste
List <int> finalList = new List <int>();
finalList = ReturnFinalList(StackOfLists, finalList, 0);
//tworze z mojej scierzki stringa
string EulerPath = "";
for (int i = 0; i < finalList.Count; i++)
{
EulerPath = EulerPath + " " + finalList[i];
}
return(EulerPath);
}
//Randomizacja grafu
public static bool RandomizeGraph(Graph oldGraph, int countChanges)
{
// Po randomizacji zmienia się najwieksza spójna składowa, dlatego resetuje
oldGraph.ResetStronglyConnections();
int connectionsCount = oldGraph.Connections.Count;
if (connectionsCount < 2)
{
return(false);
}
//for (int i = 0; i < oldGraph.Nodes.Count; ++i)
// oldGraph.Nodes[i].GraphicalStringConnections = 0;
//for (int i = 0; i < oldGraph.Connections.Count; ++i)
//{
// oldGraph.Nodes[oldGraph.Connections[i].Node1.ID].GraphicalStringConnections++;
// oldGraph.Nodes[oldGraph.Connections[i].Node2.ID].GraphicalStringConnections++;
//}
//oldGraph.Nodes.Sort((x, y) => x.GraphicalStringConnections.CompareTo(y.GraphicalStringConnections));
//if (oldGraph.Nodes.FindLastIndex(x => x.GraphicalStringConnections == 1) >= oldGraph.Nodes.Count - 2)
//{
// oldGraph.Nodes.Sort((x, y) => x.ID.CompareTo(y.ID));
// return false;
//}
//oldGraph.Nodes.Sort((x, y) => x.ID.CompareTo(y.ID));
for (int i = 0; i < connectionsCount; ++i)
{
if (oldGraph.Connections[i].Node1.ID > oldGraph.Connections[i].Node2.ID)
{
Node temp = oldGraph.Connections[i].Node1;
oldGraph.Connections[i].Node1 = oldGraph.Connections[i].Node2;
oldGraph.Connections[i].Node2 = temp;
}
}
Random rnd = new Random();
Connection emptyConnection = oldGraph.Connections.Find(x => x.Node1.ID == 123123123);
int secureCounter = 1000;
while (countChanges > 0)
{
secureCounter--;
if (secureCounter == 0)
{
return(false);
}
int id1 = rnd.Next(0, connectionsCount);
int id2 = rnd.Next(0, connectionsCount);
if (id1 == id2)
{
continue;
}
Connection c1 = oldGraph.Connections[id1];
Connection c2 = oldGraph.Connections[id2];
if (c1.Node1.ID == c2.Node1.ID || c1.Node1.ID == c2.Node2.ID || c1.Node2.ID == c2.Node1.ID ||
c1.Node2.ID == c2.Node2.ID)
{
continue;
}
Node a = c1.Node1;
Node b = c1.Node2;
Node c = c2.Node1;
Node d = c2.Node2;
if (emptyConnection == oldGraph.Connections.Find(x => x.Node1.ID == a.ID && x.Node2.ID == c.ID))
{
if (b.ID > d.ID)
{
if (emptyConnection == oldGraph.Connections.Find(x => x.Node1.ID == d.ID && x.Node2.ID == b.ID))
{
c1.Node2 = c;
c2.Node1 = d;
c2.Node2 = b;
countChanges--;
}
}
else
{
if (emptyConnection == oldGraph.Connections.Find(x => x.Node1.ID == b.ID && x.Node2.ID == d.ID))
{
c1.Node2 = c;
c2.Node1 = b;
countChanges--;
}
}
}
else if (emptyConnection == oldGraph.Connections.Find(x => x.Node1.ID == a.ID && x.Node2.ID == d.ID))
{
if (b.ID > c.ID)
{
if (emptyConnection == oldGraph.Connections.Find(x => x.Node1.ID == c.ID && x.Node2.ID == b.ID))
{
c1.Node2 = d;
c2.Node1 = c;
c2.Node2 = b;
countChanges--;
}
}
else
{
if (emptyConnection == oldGraph.Connections.Find(x => x.Node1.ID == b.ID && x.Node2.ID == c.ID))
{
c1.Node2 = d;
c2.Node1 = b;
c2.Node2 = c;
countChanges--;
}
}
}
}
return(true);
}
