private static void VerifyAllSuffixes(string[] strings, IEnumerable <Suffix> result)
{
var expectedSuffixes = new List <string>();
var expectedSources = new LazyDictionary <string, List <int> >(_ => new List <int>());
for (var i = 0; i < strings.Length; ++i)
{
var s = strings[i];
for (var j = 0; j < s.Length; ++j)
{
var suffix = s.Substring(j);
expectedSuffixes.Add(suffix);
expectedSources[suffix].Add(i);
}
}
expectedSuffixes.Sort();
var suffixes = result.ToList();
Assert.That(suffixes.Select(_ => _.Value).ToList(), Is.EqualTo(expectedSuffixes));
var grouped = suffixes.Select(_ => new { value = _.Value, source = _.SourceIndex })
.GroupBy(_ => _.value).ToDictionary(_ => _.Key, _ => _.Select(v => v.source).OrderBy(v => v).ToList());
foreach (var v in grouped)
{
Assert.That(v.Value, Is.EqualTo(expectedSources[v.Key]));
}
}
private static void TestStartingWith(string[] strings)
{
var prefixes = new HashSet <string>();
var st = new SuffixTree();
foreach (var s in strings)
{
st.Add(s);
for (var i = 0; i < s.Length; ++i)
{
for (var j = i + 1; j <= s.Length; ++j)
{
prefixes.Add(s.Substring(i, j - i));
}
}
}
st.Compact();
foreach (var prefix in prefixes)
{
var expectedSuffixes = new List <string>();
var expectedSources = new LazyDictionary <string, List <int> >(_ => new List <int>());
for (var i = 0; i < strings.Length; ++i)
{
var s = strings[i];
var pos = 0;
for (;;)
{
pos = s.IndexOf(prefix, pos);
if (pos == -1)
{
break;
}
var suffix = s.Substring(pos);
expectedSuffixes.Add(suffix);
expectedSources[suffix].Add(i);
++pos;
}
}
expectedSuffixes.Sort();
var suffixes = st.StartingWith(prefix).ToList();
Assert.That(suffixes.Select(_ => _.Value).ToList(), Is.EqualTo(expectedSuffixes));
var grouped = suffixes.Select(_ => new { value = _.Value, source = _.SourceIndex })
.GroupBy(_ => _.value).ToDictionary(_ => _.Key, _ => _.Select(v => v.source).OrderBy(v => v).ToList());
foreach (var v in grouped)
{
Assert.That(v.Value, Is.EqualTo(expectedSources[v.Key]));
}
}
Assert.That(st.StartingWith("@").Count(), Is.EqualTo(0));
VerifyAllSuffixes(strings, st.StartingWith(string.Empty));
}
public static IEnumerable <T[]> GroupTopoSort <T>(
this ICollection <T> source,
[InstantHandle] Func <T, IEnumerable <T> > dependsOnGetter,
IEqualityComparer <T> equalityComparer)
where T : notnull
{
Code.NotNull(source, nameof(source));
Code.NotNull(dependsOnGetter, nameof(dependsOnGetter));
Code.NotNull(equalityComparer, nameof(equalityComparer));
// Fast path
if (source.Count == 0)
{
yield break;
}
var dependants =
LazyDictionary.Create(
_ => new List <T>(),
equalityComparer,
false);
var workArray = new int[source.Count];
var indices = new Dictionary <T, int>(equalityComparer);
var level = new List <T>();
foreach (var(index, item) in source.WithIndex())
{
var count = 0;
foreach (var dep in dependsOnGetter(item))
{
dependants[dep].Add(item);
count++;
}
if (count == 0)
{
level.Add(item);
}
else
{
workArray[index] = count;
}
indices.Add(item, index);
}
if (level.Count == 0)
{
throw CycleException(nameof(source));
}
// Fast path
if (level.Count == workArray.Length)
{
yield return(level.ToArray());
yield break;
}
var pendingCount = workArray.Length;
while (true)
{
var nextLevel = Lazy.Create(() => new List <T>(), false);
foreach (var item in level)
{
foreach (var dep in dependants[item])
{
var pending = --workArray[indices[dep]];
if (pending == 0)
{
nextLevel.Value.Add(dep);
}
}
}
yield return(level.ToArray());
pendingCount -= level.Count;
if (pendingCount == 0)
{
yield break;
}
if (!nextLevel.IsValueCreated)
{
throw CycleException(nameof(source));
}
level = nextLevel.Value;
}
}
