public void TestGraph()
{
Random rand = new Random();
int v = rand.Next(10, 30);
Graph g = new Graph(v);
int e0 = rand.Next(10, 30);
string strs = string.Empty;
for (int i = 0; i < e0; i++)
{
int v1 = rand.Next(0, v);
int v2 = rand.Next(0, v);
string str = v1 + " - " + v2 + ",";
string str1 = v2 + " - " + v1 + ",";
if (v1 == v2 || strs.Contains(str) || strs.Contains(str1))
{
i--;
continue;
}
g.AddEdge(v1, v2);
strs += str;
}
Debug.WriteLine("input e: " + strs);
Debug.WriteLine(g.ToString());
Graph g1 = new Graph(g);
Debug.WriteLine("g1: ");
Debug.WriteLine(g1.ToString());
}
/// <summary>
/// Computes the shortest path between any one of the source vertices in sources
/// </summary>
/// <param name="g"></param>
/// <param name="s"></param>
public BreadthFirstPaths(Graph g, int s)
{
this.Marked = new bool[g.V];
this._edgeTo = new int[g.V];
this._s = s;
this.bfs(g, s);
}
private void dfs(Graph g, int v)
{
this.Marked[v] = true;
this.ID[v] = this.Count;
foreach (int w in g.Adj[v])
if (!this.Marked[w])
this.dfs(g, w);
}
private void dfs(Graph g, int v)
{
this.Marked[v] = true;
foreach (int w in g.Adj[v])
if (!this.Marked[w])
{
this._edgeTo[w] = v;
this.dfs(g, w);
}
}
/// <summary>
/// Computes the connected components of the undirected graph G.
/// </summary>
/// <param name="g"></param>
public CC(Graph g)
{
this.Marked = new bool[g.V];
this.ID = new int[g.V];
for (int v = 0; v < g.V; v++)
if (!this.Marked[v])
{
this.dfs(g, v);
this.Count++;
}
}
public Graph(Graph g)
: this(g.V)
{
this.E = g.E;
for (int v = 0; v < g.V; v++)
{
Part1.Stack<int> reverse = new Part1.Stack<int>();
foreach (int w in g.Adj[v])
reverse.Push(w);
foreach (int w in reverse)
this.Adj[v].Add(w);
}
}
private void bfs(Graph g, int s)
{
this.Marked[s] = true;
Queue<int> queue = new Queue<int>();
queue.Enqueue(s);
while (queue.Count != 0)
{
int v = queue.Dequeue();
foreach (int w in g.Adj[s])
if (!this.Marked[w])
{
this._edgeTo[w] = s;
this.Marked[w] = true;
queue.Enqueue(w);
}
}
}
/// <summary>
/// Initializes a graph from a string using the specified delimiter.
/// </summary>
/// <param name="str"></param>
/// <param name="delimiter"></param>
public SymbolGraph(string str, char delimiter)
{
this._dics = new Dictionary<string, int>();
// First pass builds the index by reading strings to associate distinct strings with an index
string[] strs = str.Split(delimiter);
for (int i = 0; i < strs.Length; i++)
if (!string.IsNullOrEmpty(strs[i]))
if (!this._dics.ContainsKey(strs[i]))
this._dics.Add(strs[i], this._dics.Count);
// inverted index to get string keys in an aray
this._keys = new string[this._dics.Count];
Array.Copy(this._dics.Keys.ToArray(), this._keys, this._dics.Count);
// second pass builds the graph by connecting first vertex on each line to all others
this.Graph = new Graph(this._dics.Count);
for (int i = 0; i < strs.Length; i++)
if (!string.IsNullOrEmpty(strs[i]))
this.Graph.AddEdge(this._dics[strs[i]], this._dics[strs[++i]]);
}
