public bool Possible()
{
Graph g = new Graph(N * 2, E, true);
TarjanSCC scc = new TarjanSCC(g);
for (int v = 0; v < N; v++)
{
if (scc.StronglyConnected(v << 1, (v << 1) ^ 1))
{
return(false);
}
}
return(true);
}
// 参考解答 连通性 + 最小生成树性质
public static IList <IList <int> > FindCriticalAndPseudoCriticalEdges_1(int n, int[][] edges)
{
int length = edges.Length;
var newEdges = edges.Select((item, index) => (X: item[0], Y: item[1], V: item[2], Index: index))
.OrderBy(item => item.V)
.ToArray();
UnionFind unionFind = new UnionFind(n);
IList <IList <int> > result = new List <IList <int> >();
for (int i = 0; i < 2; i++)
{
result.Add(new List <int>());
}
int[] label = new int[length];
int index = 0;
while (index < length)
{
int v = newEdges[index].V;
int j = index;
while (j < length && newEdges[j].V == v)
{
j++;
}
Dictionary <int, int> compToId = new Dictionary <int, int>();
int gn = 0;
for (int k = index; k < j; k++)
{
int x = newEdges[k].X;
int y = newEdges[k].Y;
if (x != y)
{
if (!compToId.ContainsKey(x))
{
compToId[x] = gn++;
}
if (!compToId.ContainsKey(y))
{
compToId[y] = gn++;
}
}
else
{
label[newEdges[k].Index] = -1;
}
}
List <int>[] gm = new List <int> [gn];
List <int>[] gmid = new List <int> [gn];
for (int k = 0; k < gn; k++)
{
gm[k] = new List <int>();
gmid[k] = new List <int>();
}
for (int k = index; k < j; k++)
{
int x = newEdges[k].X;
int y = newEdges[k].Y;
if (x == y)
{
continue;
}
int idX = compToId[x];
int idY = compToId[y];
gm[idX].Add(idY);
gmid[idX].Add(newEdges[k].Index);
gm[idY].Add(idX);
gmid[idY].Add(newEdges[k].Index);
}
List <int> bridges = new TarjanSCC(gn, gm, gmid).CuttingEdge;
foreach (int id in bridges)
{
result[0].Add(id);
label[id] = 1;
}
for (int k = index; k < j; k++)
{
unionFind.Union(newEdges[k].X, newEdges[k].Y);
}
index = j;
}
for (int i = 0; i < length; i++)
{
if (label[i] == 0)
{
result[i].Add(i);
}
}
return(result);
}
public void Run()
{
Console.WriteLine("Choose file:"); // Prompt
Console.WriteLine("1 - tinyDG.txt"); // Prompt
Console.WriteLine("2 - mediumDG.txt"); // Prompt
Console.WriteLine("or quit"); // Prompt
var fileNumber = Console.ReadLine();
string fileName;
switch (fileNumber)
{
case "1":
fileName = "tinyDG.txt";
break;
case "2":
fileName = "mediumDG.txt";
break;
case "quit":
return;
default:
return;
}
var @in = new In($"Files\\Graphs\\{fileName}");
var lines = @in.ReadAllLines();
var lineIterator = 0;
var v = 0;
var e = 0;
var edges = new List <EdgeD>();
foreach (var line in lines)
{
if (lineIterator == 0)
{
v = Convert.ToInt32(line);
}
if (lineIterator == 1)
{
e = Convert.ToInt32(line);
}
if (lineIterator > 1)
{
var lineSplitted = line.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
var ve = Convert.ToInt32(lineSplitted[0]);
var we = Convert.ToInt32(lineSplitted[1]);
var edge = new EdgeD(ve, we);
edges.Add(edge);
}
lineIterator++;
}
var digraph = new Digraph(v, e, edges);
Console.WriteLine(digraph);
var scc = new TarjanSCC(digraph);
// number of connected components
var m = scc.Count();
Console.WriteLine($"{m} components");
// compute list of vertices in each strong component
var components = new Core.Collections.Queue <Integer> [m];
for (var i = 0; i < m; i++)
{
components[i] = new Core.Collections.Queue <Integer>();
}
for (var i = 0; i < digraph.V; i++)
{
components[scc.Id(i)].Enqueue(i);
}
// print results
for (var i = 0; i < m; i++)
{
foreach (int j in components[i])
{
Console.Write($"{j} ");
}
Console.WriteLine();
}
Console.ReadLine();
}
public static void ShowCycles(int pos, Document document)
{
Dictionary <string, string> result = new Dictionary <string, string>();
// Check if initial file is a grammar.
ParsingResults pd_parser = ParsingResultsFactory.Create(document) as ParsingResults;
if (pd_parser == null)
{
throw new LanguageServerException("A grammar file is not selected. Please select one first.");
}
Transform.ExtractGrammarType egt = new Transform.ExtractGrammarType();
ParseTreeWalker.Default.Walk(egt, pd_parser.ParseTree);
bool is_grammar = egt.Type == Transform.ExtractGrammarType.GrammarType.Parser ||
egt.Type == Transform.ExtractGrammarType.GrammarType.Combined ||
egt.Type == Transform.ExtractGrammarType.GrammarType.Lexer;
if (!is_grammar)
{
throw new LanguageServerException("A grammar file is not selected. Please select one first.");
}
// Find all other grammars by walking dependencies (import, vocab, file names).
HashSet <string> read_files = new HashSet <string>
{
document.FullPath
};
Dictionary <Workspaces.Document, List <TerminalNodeImpl> > every_damn_literal =
new Dictionary <Workspaces.Document, List <TerminalNodeImpl> >();
for (; ;)
{
int before_count = read_files.Count;
foreach (string f in read_files)
{
List <string> additional = ParsingResults.InverseImports.Where(
t => t.Value.Contains(f)).Select(
t => t.Key).ToList();
read_files = read_files.Union(additional).ToHashSet();
}
foreach (string f in read_files)
{
var additional = ParsingResults.InverseImports.Where(
t => t.Key == f).Select(
t => t.Value);
foreach (var t in additional)
{
read_files = read_files.Union(t).ToHashSet();
}
}
int after_count = read_files.Count;
if (after_count == before_count)
{
break;
}
}
// Construct graph of symbol usage.
Transform.TableOfRules table = new Transform.TableOfRules(pd_parser, document);
table.ReadRules();
table.FindPartitions();
table.FindStartRules();
Digraph <string> graph = new Digraph <string>();
foreach (Transform.TableOfRules.Row r in table.rules)
{
if (!r.is_parser_rule)
{
continue;
}
graph.AddVertex(r.LHS);
}
foreach (Transform.TableOfRules.Row r in table.rules)
{
if (!r.is_parser_rule)
{
continue;
}
List <string> j = r.RHS;
//j.Reverse();
foreach (string rhs in j)
{
Transform.TableOfRules.Row sym = table.rules.Where(t => t.LHS == rhs).FirstOrDefault();
if (!sym.is_parser_rule)
{
continue;
}
DirectedEdge <string> e = new DirectedEdge <string>(r.LHS, rhs);
graph.AddEdge(e);
}
}
List <string> starts = new List <string>();
List <string> parser_lhs_rules = new List <string>();
foreach (Transform.TableOfRules.Row r in table.rules)
{
if (r.is_parser_rule)
{
parser_lhs_rules.Add(r.LHS);
if (r.is_start)
{
starts.Add(r.LHS);
}
}
}
IParseTree rule = null;
IParseTree it = pd_parser.AllNodes.Where(n =>
{
if (!(n is ANTLRv4Parser.ParserRuleSpecContext || n is ANTLRv4Parser.LexerRuleSpecContext))
{
return(false);
}
Interval source_interval = n.SourceInterval;
int a = source_interval.a;
int b = source_interval.b;
IToken ta = pd_parser.TokStream.Get(a);
IToken tb = pd_parser.TokStream.Get(b);
var start = ta.StartIndex;
var stop = tb.StopIndex + 1;
return(start <= pos && pos < stop);
}).FirstOrDefault();
rule = it;
var k = (ANTLRv4Parser.ParserRuleSpecContext)rule;
var tarjan = new TarjanSCC <string, DirectedEdge <string> >(graph);
List <string> ordered = new List <string>();
var sccs = tarjan.Compute();
StringBuilder sb = new StringBuilder();
sb.AppendLine("Cycles in " + document.FullPath);
var done = new List <IEnumerable <string> >();
foreach (var scc in sccs)
{
if (scc.Value.Count() <= 1)
{
continue;
}
if (!done.Contains(scc.Value))
{
foreach (var s in scc.Value)
{
sb.Append(" ");
sb.Append(s);
}
sb.AppendLine();
sb.AppendLine();
done.Add(scc.Value);
}
}
//var scc = sccs[k.RULE_REF().ToString()];
//foreach (var v in scc)
//{
// ordered.Add(v);
//}
}
