/**
* Adjusts heap to maintain the heap property.
* @param heap
* @param last index to adjust up to.
* @param position index where adjustment starts.
* @param compare pointer to compare function.
*/
void adjustHeap(DynamicArray* heap, int last, int position, compareFunction compare)
{
int leftChild = 2 * position + 1;
int rightChild = 2 * position + 2;
int smallestChild;
/* we have two children */
if (rightChild < last) {
if (compare(dyGet(heap, leftChild), dyGet(heap,rightChild)) == -1)
smallestChild = leftChild;
else
smallestChild = rightChild;
//get index of smallest child
if (compare(dyGet(heap, position), dyGet(heap, smallestChild)) == 1) {
dySwap(heap, position, smallestChild);
adjustHeap(heap, last, smallestChild, compare);
}
}
else if (leftChild < last) {
if (compare(dyGet(heap, position), dyGet(heap, leftChild)) == 1) {
dySwap(heap, position, leftChild);
adjustHeap(heap, last, leftChild, compare);
}
}
}
void shuffle(DynamicArray* array)
{
for (int i = 0; i < dySize(array); i++)
{
int j = rand() % dySize(array);
dySwap(array, i, j);
}
}
void dyAddAt(DynamicArray* array, TYPE value, int position)
{
assert(position <= array->size);
dyAdd(array, value);
int i;
for (i = array->size - 1; i > position; i--)
{
dySwap(array, i, i - 1);
}
}
/**
* Adds an element to the heap.
* @param heap
* @param value value to be added to heap.
* @param compare pointer to compare function.
*/
void dyHeapAdd(DynamicArray* heap, TYPE value, compareFunction compare)
{
//int pos = dySize(heap) - 1;
dyAdd(heap, value);
int pos = dySize(heap) - 1;
int parent;
while (pos > 0) {
parent = (pos - 1) / 2;
if(compare(dyGet(heap, pos), dyGet(heap, parent)) == -1){
dySwap(heap, pos, parent);
pos = parent;
}
else
break;
}
}