public Digraph reverse()
{
Digraph R = new Digraph(V);
for (int v = 0; v < V; v++)
foreach (var w in getAdj(v))
R.addEdge(w, v);
return R;
}
private char[] find(String[] orderStrings)
{
Digraph g = new Digraph(26);
int j = 0;
for (int i = 0; i < orderStrings.Length - 1; i++)
{
string high = orderStrings[i + 1];
string low = orderStrings[i];
int minLength = Math.Min(low.Length, high.Length);
for (j = 0; j < minLength; j++)
{
if (low[j] == high[j])
continue;
if (low[j] != high[j])
g.addEdge(get(low[j]), get(high[j]));
}
}
DirectedCycle cycle = new DirectedCycle(g);
if (cycle.hasCycle()) {
foreach (var c in cycle.getCycle())
Console.Write(c + " -> ");
Console.WriteLine();
return null;
}
List<char> orders = new List<char>();
DFSDiagraph dfs = new DFSDiagraph(g);
foreach (var v in dfs.sort()) {
orders.Add(get(v));
}
return orders.ToArray();
}