public bool IsTree(CheckGraphResult validation)
{
if (verticesNumber <= 1)
{
return true;
}
var visited = new bool[verticesNumber];
if (HasCycle(0, visited, -1, validation))
{
return false;
}
for (var i = 0; i < visited.Length; i++)
{
if (!visited[i])
{
validation.DisconnectedWordIds.Add(wordToVertexMapping.Single(p => p.Value == i).Key);
return false;
}
}
return true;
}
private bool HasCycle(int vertex, bool[] visited, int parent, CheckGraphResult validation)
{
visited[vertex] = true;
if (!adjencyList.ContainsKey(vertex))
{
return false;
}
foreach (var v in adjencyList[vertex])
{
if (!visited[v])
{
if (HasCycle(v, visited, vertex, validation))
{
var cycle = new List<string>();
for (var i = 0; i < visited.Length; i++)
{
if (visited[i])
cycle.Add(wordToVertexMapping.Single(p => p.Value == i).Key);
}
cycle.Add(wordToVertexMapping.Single(p => p.Value == v).Key);
validation.Cycles.Add(cycle);
return true;
}
}
else if (v != parent)
{
return true;
}
}
return false;
}