/// <summary>
/// Removes the min element from the heap.
/// </summary>
/// <param name="keyValue">If the operation is successful, contains the minimum element in the array.</param>
/// <param name="heapArrayLength">The length of the heap array. </param>
/// <returns>True in case of success, and false otherwise</returns>
public override bool TryRemoveRoot(out KeyValuePair <TKey, TValue> keyValue, int heapArrayLength)
{
keyValue = new KeyValuePair <TKey, TValue>((TKey)typeof(TKey).GetField("MinValue").GetValue(null), default(TValue)); // T.MinValue;
/* If array is empty, returns false. */
if (heapArrayLength == 0)
{
return(false);
}
/* If array has only one element left, it is the minimum value, and clear the array after removing it.*/
if (heapArrayLength == 1)
{
keyValue = HeapArray[0];
HeapArray.Clear();;
return(true);
}
/* If array has more than 1 element, the next instructions are executed. */
keyValue = HeapArray[0]; /* In a minHeap the minimum value is always in the root, which is at index 0.*/
HeapArray[0] = HeapArray[heapArrayLength - 1]; /* Move the last element to the place of root, and then bubble down. */
HeapArray.RemoveAt(heapArrayLength - 1); /* Removing the last element, as it is now placed in the root's position, and needs to be bubbled down.*/
BubbleDown_Recursively(0, heapArrayLength - 1); /* Call this method to bubble down the (new) root.*/ /* Also notice that the array is shorter by one value now, thus the new array length is one smaller. */
return(true);
}
/// <summary>
/// Removes the min element from the heap.
/// </summary>
/// <param name="keyValue">If the operation is successful, contains the minimum element in the array.</param>
/// <param name="heapArrayLength">The length of the heap array. </param>
/// <returns></returns>
public override bool TryRemoveRoot(out KeyValuePair <TKey, TValue> keyValue, int heapArrayLength)
{
keyValue = new KeyValuePair <TKey, TValue>((TKey)typeof(TKey).GetField("MinValue").GetValue(null), default(TValue));
if (heapArrayLength == 0)
{
return(false);
}
if (heapArrayLength == 1)
{
keyValue = HeapArray[0];
HeapArray.Clear();
return(true);
}
keyValue = HeapArray[0];
HeapArray[0] = HeapArray[heapArrayLength - 1];
HeapArray.RemoveAt(heapArrayLength - 1);
BubbleDownMin_Recursively(0, heapArrayLength - 1); /* Calling this method, because this is a min-max heap and 0 is expected to be on a min level.*/ /* Also notice that the array is shorter by one value now, thus the new array length is one smaller. */
return(true);
}
/// <summary>
/// Removes the max element from the heap.
/// </summary>
/// <param name="keyValue">If the operation is successful, contains the maximum element in the array.</param>
/// <param name="heapArrayLength">The length of the heap array. </param>
/// <returns>True in case of success, and false otherwise</returns>
public override bool TryRemoveRoot(out KeyValuePair <TKey, TValue> keyValue, int heapArrayLength)
{
keyValue = new KeyValuePair <TKey, TValue>((TKey)typeof(TKey).GetField("MaxValue").GetValue(null), default(TValue));
if (heapArrayLength == 0)
{
return(false);
}
if (heapArrayLength == 1)
{
keyValue = HeapArray[0];
HeapArray.Clear();
return(true);
}
keyValue = HeapArray[0];
HeapArray[0] = HeapArray[heapArrayLength - 1];
HeapArray.RemoveAt(heapArrayLength - 1);
BubbleDown_Recursively(0, heapArrayLength - 1); /* notice that the array is shorter by one value now, thus the new array length is one smaller. */
return(true);
}
