public void Push(HeapNode node)
{
if (++_tail >= _arr.Length)
{
throw new IndexOutOfRangeException($"Cannot insert value. Array capacity: {_arr.Length} Index: {_tail}");
}
_arr[_tail] = node;
int currentIndex = _tail;
int parentIndex = GetParetnIndex(_tail);
while (parentIndex >= 0 && _arr[currentIndex].Key < _arr[parentIndex].Key)
{
_arr[currentIndex] = _arr[parentIndex];
_arr[parentIndex] = node;
currentIndex = parentIndex;
parentIndex = GetParetnIndex(currentIndex);
}
}
public HeapNode Pop()
{
if (_tail == -1)
{
throw new IndexOutOfRangeException("Heap is empty");
}
HeapNode top = _arr[0];
_arr[0] = _arr[_tail];
_arr[_tail] = null;
_tail--;
int currentIndex = 0;
while (LeftLeafExists(currentIndex))
{
int biggestIndex = GetLeftLeafIndex(currentIndex);
if (RightLeafExists(currentIndex) && _arr[GetRightLeafIndex(currentIndex)].Key > _arr[biggestIndex].Key)
{
biggestIndex = GetRightLeafIndex(currentIndex);
}
if (_arr[currentIndex].Key > _arr[biggestIndex].Key)
{
break;
}
// swap
var tmp = _arr[currentIndex];
_arr[currentIndex] = _arr[biggestIndex];
_arr[biggestIndex] = tmp;
// go further
currentIndex = biggestIndex;
}
return(top);
}
public void Push(HeapNode node)
{
if (++_tail >= _arr.Length)
{
throw new IndexOutOfRangeException($"Cannot insert value. Array capacity: {_arr.Length} Index: {_tail}");
}
_arr[_tail] = node;
// walk up the tree and swap current value with parent if current value is greater than parent
int currentIndex = _tail;
int parentIndex = GetParent(_tail);
while (parentIndex >= 0 && _arr[currentIndex].Key > _arr[parentIndex].Key)
{
_arr[currentIndex] = _arr[parentIndex];
_arr[parentIndex] = node; // do not need to use tmp
currentIndex = parentIndex;
parentIndex = GetParent(currentIndex);
}
}
public MinHeap(int size)
{
_arr = new HeapNode[size];
}
