public static ForestDisjointSet<int> Create(int[] elements, int[] unions)
{
var ds = new ForestDisjointSet<int>();
for (int i = 0; i < elements.Length; ++i)
ds.MakeSet(i);
for (int i = 0; i+1 < unions.Length; i+=2)
{
PexAssume.IsTrue(ds.Contains(unions[i]));
PexAssume.IsTrue(ds.Contains(unions[i+1]));
ds.Union(unions[i], unions[i+1]);
}
return ds;
}
public void Contains()
{
ContainsTest(1, 2);
ContainsTest(
new TestVertex("1"),
new TestVertex("2"));
ContainsTest(
new EquatableTestVertex("1"),
new EquatableTestVertex("2"));
#region Local function
void ContainsTest <TValue>(TValue value1, TValue value2)
{
var set = new ForestDisjointSet <TValue>();
Assert.IsFalse(set.Contains(value1));
Assert.IsFalse(set.Contains(value2));
set.MakeSet(value1);
Assert.IsTrue(set.Contains(value1));
Assert.IsFalse(set.Contains(value2));
set.MakeSet(value2);
Assert.IsTrue(set.Contains(value1));
Assert.IsTrue(set.Contains(value2));
set.Union(value1, value2);
Assert.IsTrue(set.Contains(value1));
Assert.IsTrue(set.Contains(value2));
}
#endregion
}
public void Unions(int elementCount, [PexAssumeNotNull]KeyValuePair<int,int>[] unions)
{
PexAssume.IsTrue(0 < elementCount);
PexSymbolicValue.Minimize(elementCount);
PexAssume.TrueForAll(
unions,
u => 0 <= u.Key && u.Key < elementCount &&
0 <= u.Value && u.Value < elementCount
);
var target = new ForestDisjointSet<int>();
// fill up with 0..elementCount - 1
for (int i = 0; i < elementCount; i++)
{
target.MakeSet(i);
Assert.IsTrue(target.Contains(i));
Assert.AreEqual(i + 1, target.ElementCount);
Assert.AreEqual(i + 1, target.SetCount);
}
// apply Union for pairs unions[i], unions[i+1]
for (int i = 0; i < unions.Length; i++)
{
var left = unions[i].Key;
var right= unions[i].Value;
var setCount = target.SetCount;
bool unioned = target.Union(left, right);
// should be in the same set now
Assert.IsTrue(target.AreInSameSet(left, right));
// if unioned, the count decreased by 1
PexAssert.ImpliesIsTrue(unioned, () => setCount - 1 == target.SetCount);
}
}
public void Contains_Throws()
{
var set = new ForestDisjointSet <TestVertex>();
// ReSharper disable once ReturnValueOfPureMethodIsNotUsed
// ReSharper disable once AssignNullToNotNullAttribute
Assert.Throws <ArgumentNullException>(() => set.Contains(null));
}
public static ForestDisjointSet <int> Create([NotNull] int[] elements, [NotNull] int[] unions)
{
var sets = new ForestDisjointSet <int>();
for (int i = 0; i < elements.Length; ++i)
{
sets.MakeSet(i);
}
for (int i = 0; i + 1 < unions.Length; i += 2)
{
Assert.IsTrue(sets.Contains(unions[i]));
Assert.IsTrue(sets.Contains(unions[i + 1]));
sets.Union(unions[i], unions[i + 1]);
}
return(sets);
}
private void Unions(int elementCount, [NotNull] KeyValuePair <int, int>[] unions)
{
Assert.IsTrue(0 < elementCount);
QuikGraphAssert.TrueForAll(
unions,
u => 0 <= u.Key &&
u.Key < elementCount &&
0 <= u.Value &&
u.Value < elementCount);
var target = new ForestDisjointSet <int>();
// Fill up with 0..elementCount - 1
for (int i = 0; i < elementCount; ++i)
{
target.MakeSet(i);
Assert.IsTrue(target.Contains(i));
Assert.AreEqual(i + 1, target.ElementCount);
Assert.AreEqual(i + 1, target.SetCount);
}
// Apply Union for pairs unions[i], unions[i+1]
foreach (KeyValuePair <int, int> pair in unions)
{
int left = pair.Key;
int right = pair.Value;
int setCount = target.SetCount;
bool unioned = target.Union(left, right);
// Should be in the same set now
Assert.IsTrue(target.AreInSameSet(left, right));
// If unioned, the count decreased by 1
QuikGraphAssert.ImpliesIsTrue(unioned, () => setCount - 1 == target.SetCount);
}
}
