public void MinHeapInitialises()
{
int testOrder = 2;
var minDHeap = new MinDHeap <int>(testOrder);
Assert.IsNotNull(minDHeap);
}
internal static IEnumerable <T> MergeBy <T, TKey>(IEnumerable <IEnumerable <T> > lists, Func <T, TKey> keySelector, IComparer <TKey> comparer, bool descending)
{
var initialItems = lists
.Select(l => l.GetEnumerator())
.Where(i => i.MoveNext());
IComparer <T> keyComparer = comparer != null ?
new KeySelectorComparer <T, TKey>(keySelector, comparer) :
new KeySelectorComparer <T, TKey>(keySelector);
var enumerableComparer = new EnumeratorComparer <T>(keyComparer);
DHeap <IEnumerator <T> > heap;
if (descending)
{
heap = new MaxDHeap <IEnumerator <T> >(2, initialItems, enumerableComparer);
}
else
{
heap = new MinDHeap <IEnumerator <T> >(2, initialItems, enumerableComparer);
}
while (!heap.IsEmpty)
{
var i = heap.RemoveRoot();
yield return(i.Current);
if (i.MoveNext())
{
heap.Insert(i);
}
}
}
public void MinHeapInitialisesAndInsertsSpecifiedCollection()
{
int testOrder = 2;
IList <int> testCollection = new List <int> {
50, 51, 38, 37, 23, 11, 5, 3
};
var minDHeap = new MinDHeap <int>(testOrder, testCollection.Randomize());
Assert.AreEqual(testCollection.Count, minDHeap.Count);
}
public void MinHeapRemoveRootReturnsSmallestValue()
{
int testOrder = 2;
IList <int> testCollection = new List <int> {
50, 51, 38, 37, 23, 11, 5, 3
};
var minDHeap = new MinDHeap <int>(testOrder, testCollection.Randomize());
int root = minDHeap.RemoveRoot();
Assert.AreEqual(3, root);
}
public void MinHeapMovesNextSmallestValueToRootAfterRemoveRoot()
{
int testOrder = 2;
IList <int> testCollection = new List <int> {
50, 51, 38, 37, 23, 11, 5, 3
};
var minDHeap = new MinDHeap <int>(testOrder, testCollection.Randomize());
minDHeap.RemoveRoot();
int newRoot = minDHeap.Peek();
Assert.AreEqual(5, newRoot);
}
public void MinHeapDoesNotInsertItemAsRootIfItemIsLargerThanOriginalRoot()
{
int testOrder = 2;
IList <int> testCollection = new List <int> {
50, 51, 38, 37, 23, 11, 5, 3
};
var minDHeap = new MinDHeap <int>(testOrder, testCollection.Randomize());
int originalRoot = minDHeap.Peek();
minDHeap.Insert(4);
int newRoot = minDHeap.Peek();
Assert.AreEqual(3, originalRoot);
Assert.AreEqual(3, newRoot);
}
public void MinHeapSupportsConsumingEnumerable()
{
int testOrder = 2;
IList <int> testCollection = new List <int> {
50, 51, 38, 37, 23, 11, 5, 3
};
var minDHeap = new MinDHeap <int>(testOrder, testCollection.Randomize());
var consumingEnumerator = minDHeap.GetConsumingEnumerable().GetEnumerator();
Assert.DoesNotThrow(() =>
{
while (consumingEnumerator.MoveNext())
{
//ignore empty block
}
});
}
public void MinHeapConsumingEnumerableRemovesAllElements()
{
const int expectedCount = 0;
int testOrder = 2;
IList <int> testCollection = new List <int> {
50, 51, 38, 37, 23, 11, 5, 3
};
var minDHeap = new MinDHeap <int>(testOrder, testCollection.Randomize());
var consumingEnumerator = minDHeap.GetConsumingEnumerable().GetEnumerator();
while (consumingEnumerator.MoveNext())
{
//ignore empty block
}
Assert.AreEqual(expectedCount, minDHeap.Count);
}
public void MinHeapInsertsItemInCollectionAsRootIfItemIsSmallerThanOriginalRoot()
{
int testOrder = 2;
IList <int> testCollection = new List <int> {
50, 51, 38, 37, 23, 11, 5, 3
};
IList <int> newCollection = new List <int> {
2, 4, 6, 8, 10, 12, 14, 16, 18
};
var minDHeap = new MinDHeap <int>(testOrder, testCollection.Randomize());
int originalRoot = minDHeap.Peek();
minDHeap.InsertRange(newCollection.Randomize());
int newRoot = minDHeap.Peek();
Assert.AreEqual(3, originalRoot);
Assert.AreEqual(2, newRoot);
}
