public void LinearHeapFromArray_ValidArray_HeapSorted()
{
// arrange
int[] data = new int[] { 1, 2, 3, 4, 5, 6, 7 };
// act
MaxHeap heap = new MaxHeap(data);
// assert
ValidateSorting(heap);
}
public void Add_SortedElements_ReturnsExpected()
{
// arrange
MaxHeap heap = new MaxHeap(1000);
// act
heap.Add(3);
heap.Add(2);
heap.Add(1);
// assert
Assert.AreEqual(3, heap.Data.ElementAt(0));
Assert.AreEqual(2, heap.Data.ElementAt(1));
Assert.AreEqual(1, heap.Data.ElementAt(2));
}
public void Add_RandomElements_LevelsSorted()
{
// arrange
const int heapSize = 1000000;
MaxHeap heap = new MaxHeap(heapSize);
// act
Random r = new Random(heapSize);
for (int i = 0; i < heapSize; i++)
{
heap.Add(r.Next());
}
// assert
ValidateSorting(heap);
}
public void Remove_HalfRandomElements_HeapSorted()
{
// arrange
const int heapSize = 10;
MaxHeap heap = new MaxHeap(heapSize);
// act
Random r = new Random(heapSize);
for (int i = 0; i < heapSize; i++)
{
heap.Add(r.Next() % 10);
}
int j = heapSize / 2;
while (j >= 0)
{
heap.RemoveAt(0);
j--;
}
// assert
ValidateSorting(heap);
}
public void LinearHeapFromRandomArray_ValidArray_HeapSorted()
{
// arrange
Random r = new Random(1000);
int[] data = Enumerable.Range(0, 1000000).Select(_ => r.Next()).ToArray();
// act
MaxHeap heap = new MaxHeap(data);
// assert
ValidateSorting(heap);
}
/// <summary>
/// Validates the sorting of a heap, ensuring each node's children are less than the parent.
/// </summary>
/// <param name="heap">The heap to validate.</param>
private static void ValidateSorting(MaxHeap heap)
{
Queue<int> n = new Queue<int>();
n.Enqueue(0);
while (n.Count > 0)
{
int i = n.Dequeue();
int left = i * 2 + 1;
int right = i * 2 + 2;
if (left < heap.Size)
{
Assert.IsTrue(heap.Data[i] >= heap.Data[left]);
n.Enqueue(left);
}
if (right < heap.Size)
{
Assert.IsTrue(heap.Data[i] >= heap.Data[right]);
n.Enqueue(right);
}
}
}
public void Remove_RemoveAllFromTail_EmptyHeap()
{
// arrange
MaxHeap heap = new MaxHeap(1000);
// act
heap.Add(3);
heap.Add(2);
heap.Add(1);
heap.RemoveAt(2);
heap.RemoveAt(1);
heap.RemoveAt(0);
// assert
Assert.AreEqual(0, heap.Size);
}
public void Remove_RandomElements_EmptyHeap()
{
// arrange
const int heapSize = 1000000;
MaxHeap heap = new MaxHeap(heapSize);
// act
Random r = new Random(heapSize);
for (int i = 0; i < heapSize; i++)
{
heap.Add(r.Next());
}
int j = heapSize - 1;
while (j >= 0)
{
heap.RemoveAt(0);
j--;
}
// assert
Assert.AreEqual(0, heap.Size);
}