private static void testBigMerge()
{
int maxRank = 20;
int trials = 10000;
int numElems = 1 << maxRank; // Grows exponentially
DisjointSet ds = new DisjointSet(numElems);
for (int level = 0; level < maxRank; level++)
{
int mergeStep = 1 << level;
int incrStep = mergeStep * 2;
for (int i = 0; i < numElems; i += incrStep)
{
assert(!ds.AreInSameSet(i, i + mergeStep));
assert(ds.MergeSets(i, i + mergeStep));
}
// Now we have a bunch of sets of size 2^(level+1)
// Do random tests
int mask = -incrStep; // 0b11...100...00
for (int i = 0; i < trials; i++)
{
int j = rand.Next(numElems);
int k = rand.Next(numElems);
bool expect = (j & mask) == (k & mask);
assert(ds.AreInSameSet(j, k) == expect);
}
}
}
public void AlreadyMergedItems()
{
var data = new[] { "A", "B", "C", };
var disjointSet = new DisjointSet <string>(data);
disjointSet.Union("A", "B");
Assert.True(disjointSet.AreInSameSet("A", "B"));
Assert.False(disjointSet.AreInSameSet("A", "C"));
}
/*---- Test suite ----*/
private static void testNew()
{
DisjointSet ds = new DisjointSet(10);
assert(ds.GetNumberOfSets() == 10);
assert(ds.GetSizeOfSet(0) == 1);
assert(ds.GetSizeOfSet(2) == 1);
assert(ds.GetSizeOfSet(9) == 1);
assert(ds.AreInSameSet(0, 0));
assert(!ds.AreInSameSet(0, 1));
assert(!ds.AreInSameSet(9, 3));
ds.CheckStructure();
}
/*---- Test suite ----*/
private static void TestNew()
{
DisjointSet ds = new DisjointSet(10);
AssertEquals(10, ds.NumberOfSets);
AssertEquals(1, ds.GetSizeOfSet(0));
AssertEquals(1, ds.GetSizeOfSet(2));
AssertEquals(1, ds.GetSizeOfSet(9));
AssertTrue(ds.AreInSameSet(0, 0));
AssertFalse(ds.AreInSameSet(0, 1));
AssertFalse(ds.AreInSameSet(9, 3));
ds.CheckStructure();
}
private static void testAgainstNaiveRandomly()
{
int trials = 1000;
int iterations = 3000;
int numElems = 300;
for (int i = 0; i < trials; i++)
{
NaiveDisjointSet nds = new NaiveDisjointSet(numElems);
DisjointSet ds = new DisjointSet(numElems);
for (int j = 0; j < iterations; j++)
{
int k = rand.Next(numElems);
int l = rand.Next(numElems);
assert(ds.GetSizeOfSet(k) == nds.GetSizeOfSet(k));
assert(ds.AreInSameSet(k, l) == nds.AreInSameSet(k, l));
if (rand.NextDouble() < 0.1)
{
assert(ds.MergeSets(k, l) == nds.MergeSets(k, l));
}
assert(nds.GetNumberOfSets() == ds.GetNumberOfSets());
if (rand.NextDouble() < 0.001)
{
ds.CheckStructure();
}
}
ds.CheckStructure();
}
}
private static void testMerge()
{
DisjointSet ds = new DisjointSet(10);
assert(ds.MergeSets(0, 1));
ds.CheckStructure();
assert(ds.GetNumberOfSets() == 9);
assert(ds.AreInSameSet(0, 1));
assert(ds.MergeSets(2, 3));
ds.CheckStructure();
assert(ds.GetNumberOfSets() == 8);
assert(ds.AreInSameSet(2, 3));
assert(!ds.MergeSets(2, 3));
ds.CheckStructure();
assert(ds.GetNumberOfSets() == 8);
assert(!ds.AreInSameSet(0, 2));
assert(ds.MergeSets(0, 3));
ds.CheckStructure();
assert(ds.GetNumberOfSets() == 7);
assert(ds.AreInSameSet(0, 2));
assert(ds.AreInSameSet(3, 0));
assert(ds.AreInSameSet(1, 3));
}
private static void TestMerge()
{
DisjointSet ds = new DisjointSet(10);
AssertTrue(ds.MergeSets(0, 1));
ds.CheckStructure();
AssertEquals(9, ds.NumberOfSets);
AssertTrue(ds.AreInSameSet(0, 1));
AssertTrue(ds.MergeSets(2, 3));
ds.CheckStructure();
AssertEquals(8, ds.NumberOfSets);
AssertTrue(ds.AreInSameSet(2, 3));
AssertFalse(ds.MergeSets(2, 3));
ds.CheckStructure();
AssertEquals(8, ds.NumberOfSets);
AssertFalse(ds.AreInSameSet(0, 2));
AssertTrue(ds.MergeSets(0, 3));
ds.CheckStructure();
AssertEquals(7, ds.NumberOfSets);
AssertTrue(ds.AreInSameSet(0, 2));
AssertTrue(ds.AreInSameSet(3, 0));
AssertTrue(ds.AreInSameSet(1, 3));
}