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Hello Could someone Help me to find the solution for find all cycles in nondirected graph.

I am working with C# VS 2017, ASP.Net 5.2.60618.0

Tanks so much for Your Help.

LEG.

**What I have tried:**

I searched in Google and find a solution proposal but theare many error in my VS C# IDE. here a Copy. I am don't know how to correct the errors.

Thanks again.

namespace akCyclesInUndirectedGraphs

{

class Program

{

// Graph modelled as list of edges

static int[,] graph =

{

{1, 2}, {1, 3}, {1, 4}, {2, 3},

{3, 4}, {2, 6}, {4, 6}, {7, 8},

{8, 9}, {9, 7}

};

static List<int[]> cycles = new List<int[]>();

// static void Main(string[] args)

// {

for (int i = 0; i < graph.GetLength(0); i++)

for (int j = 0; j < graph.GetLength(1); j++)

{

findNewCycles(new int[] {graph[i, j]});

}

foreach (int[] cy in cycles)

{

string s = "" + cy[0];

for (int i = 1; i < cy.Length; i++)

s += "," + cy[i];

Console.WriteLine(s);

}

// }

static void findNewCycles(int[] path)

{

int n = path[0];

int x;

int[] sub = new int[path.Length + 1];

for (int i = 0; i < graph.GetLength(0); i++)

for (int y = 0; y <= 1; y++)

if (graph[i, y] == n)

// edge referes to our current node

{

x = graph[i, (y + 1) % 2];

if (!visited(x, path))

// neighbor node not on path yet

{

sub[0] = x;

Array.Copy(path, 0, sub, 1, path.Length);

// explore extended path

findNewCycles(sub);

}

else if ((path.Length > 2) && (x == path[path.Length - 1]))

// cycle found

{

int[] p = normalize(path);

int[] inv = invert(p);

if (isNew(p) && isNew(inv))

cycles.Add(p);

}

}

}

static bool equals(int[] a, int[] b)

{

bool ret = (a[0] == b[0]) && (a.Length == b.Length);

for (int i = 1; ret && (i < a.Length); i++)

if (a[i] != b[i])

{

ret = false;

}

return ret;

}

static int[] invert(int[] path)

{

int[] p = new int[path.Length];

for (int i = 0; i < path.Length; i++)

p[i] = path[path.Length - 1 - i];

return normalize(p);

}

// rotate cycle path such that it begins with the smallest node

static int[] normalize(int[] path)

{

int[] p = new int[path.Length];

int x = smallest(path);

int n;

Array.Copy(path, 0, p, 0, path.Length);

while (p[0] != x)

{

n = p[0];

Array.Copy(p, 1, p, 0, p.Length - 1);

p[p.Length - 1] = n;

}

return p;

}

static bool isNew(int[] path)

{

bool ret = true;

foreach(int[] p in cycles)

if (equals(p, path))

{

ret = false;

break;

}

return ret;

}

static int smallest(int[] path)

{

int min = path[0];

foreach (int p in path)

if (p < min)

min = p;

return min;

}

static bool visited(int n, int[] path)

{

bool ret = false;

foreach (int p in path)

if (p == n)

{

ret = true;

break;

}

return ret;

}

}

}

//

//The cycles for the demo graph:

//

//

//1,3,2

//1,4,3,2

//1,4,6,2

//1,3,4,6,2

//1,4,6,2,3

//1,4,3

//2,6,4,3

//7,9,8

I am working with C# VS 2017, ASP.Net 5.2.60618.0

Tanks so much for Your Help.

LEG.

I searched in Google and find a solution proposal but theare many error in my VS C# IDE. here a Copy. I am don't know how to correct the errors.

Thanks again.

namespace akCyclesInUndirectedGraphs

{

class Program

{

// Graph modelled as list of edges

static int[,] graph =

{

{1, 2}, {1, 3}, {1, 4}, {2, 3},

{3, 4}, {2, 6}, {4, 6}, {7, 8},

{8, 9}, {9, 7}

};

static List<int[]> cycles = new List<int[]>();

// static void Main(string[] args)

// {

for (int i = 0; i < graph.GetLength(0); i++)

for (int j = 0; j < graph.GetLength(1); j++)

{

findNewCycles(new int[] {graph[i, j]});

}

foreach (int[] cy in cycles)

{

string s = "" + cy[0];

for (int i = 1; i < cy.Length; i++)

s += "," + cy[i];

Console.WriteLine(s);

}

// }

static void findNewCycles(int[] path)

{

int n = path[0];

int x;

int[] sub = new int[path.Length + 1];

for (int i = 0; i < graph.GetLength(0); i++)

for (int y = 0; y <= 1; y++)

if (graph[i, y] == n)

// edge referes to our current node

{

x = graph[i, (y + 1) % 2];

if (!visited(x, path))

// neighbor node not on path yet

{

sub[0] = x;

Array.Copy(path, 0, sub, 1, path.Length);

// explore extended path

findNewCycles(sub);

}

else if ((path.Length > 2) && (x == path[path.Length - 1]))

// cycle found

{

int[] p = normalize(path);

int[] inv = invert(p);

if (isNew(p) && isNew(inv))

cycles.Add(p);

}

}

}

static bool equals(int[] a, int[] b)

{

bool ret = (a[0] == b[0]) && (a.Length == b.Length);

for (int i = 1; ret && (i < a.Length); i++)

if (a[i] != b[i])

{

ret = false;

}

return ret;

}

static int[] invert(int[] path)

{

int[] p = new int[path.Length];

for (int i = 0; i < path.Length; i++)

p[i] = path[path.Length - 1 - i];

return normalize(p);

}

// rotate cycle path such that it begins with the smallest node

static int[] normalize(int[] path)

{

int[] p = new int[path.Length];

int x = smallest(path);

int n;

Array.Copy(path, 0, p, 0, path.Length);

while (p[0] != x)

{

n = p[0];

Array.Copy(p, 1, p, 0, p.Length - 1);

p[p.Length - 1] = n;

}

return p;

}

static bool isNew(int[] path)

{

bool ret = true;

foreach(int[] p in cycles)

if (equals(p, path))

{

ret = false;

break;

}

return ret;

}

static int smallest(int[] path)

{

int min = path[0];

foreach (int p in path)

if (p < min)

min = p;

return min;

}

static bool visited(int n, int[] path)

{

bool ret = false;

foreach (int p in path)

if (p == n)

{

ret = true;

break;

}

return ret;

}

}

}

//

//The cycles for the demo graph:

//

//

//1,3,2

//1,4,3,2

//1,4,6,2

//1,3,4,6,2

//1,4,6,2,3

//1,4,3

//2,6,4,3

//7,9,8

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Improve questionto update your question.So that everyone can pay attention to this information.

Fortunately I found the error. I forget to copy "using SystemCollections.Generic;" I copy that and all errors go missing. erroneously I supouse my C# VS 2017 take care about.

Today all is working fine.

Thanks for Your Time.

Best Regarads

LEG

Fortunately I found the error. I forget to copy "using SystemCollections.Generic;" I copy that and all errors go missing. erroneously I supouse my C# VS 2017 take care about.

Today all is working fine.

Thanks for Your Time.

Best Regarads

LEG