void heapRebuild(int rootIndex, std::vector<int> &HEAP, int HEAP_SIZE){
//std::cout<<"heapRebuild_start\n";
if(!isLeaf(rootIndex, HEAP_SIZE)){
int largerChildIndex=(2*rootIndex)+1;
if(hasRightChild(rootIndex, HEAP_SIZE)){
int rightChildIndex=largerChildIndex+1;
if(HEAP[rightChildIndex]>HEAP[largerChildIndex]){
counter++;
largerChildIndex=rightChildIndex;
}
}
if(HEAP[rootIndex]<HEAP[largerChildIndex]){
counter++;
int temp = HEAP[rootIndex];
HEAP[rootIndex]=HEAP[largerChildIndex];
HEAP[largerChildIndex]=temp;
heapRebuild(largerChildIndex, HEAP, HEAP_SIZE);
}
}
//std::cout<<"heapRebuild_end\n";
}
/* RECURSION ALERT:
* This functions recursively bubbles down the new root after dequeueing until the binary
* search tree is rebalanced.
*/
void HeapPriorityQueue::bubbleDownSwap(string* parent, int index, string* child, string** &elements){
/* BASE CASE:
* We can stop swapping elements down as soon as the child is bigger than the parent element.
*/
if(child > parent || index > size()){
return;
}
/* RECURSIVE STEP:
* If the parent is bigger than either of the children, we need to swap the parent with the child
* it is smaller than. If both children are equal, we will automatically swap with the left child.
*/
if(hasLeftChild(index, elements)){
string* leftChild = elements[index * 2];
//If the left child is smaller than the parent, swap down.
if(leftChild < parent){
//Obtain original values/
string* original = parent;
parent = leftChild;
//Swap the two.
child = original;
bubbleDownSwap(parent, index * 2, child, elements);
}
}
if(hasRightChild(index, elements)){
string* rightChild = elements[index * 2 + 1];
if(rightChild < parent){
//Obtain original values.
string* original = parent;
parent = rightChild;
//Swap the two.
child = original;
bubbleDownSwap(parent, index * 2 + 1, child, elements);
}
}
}
bool isLeaf(TreeNode* &node)
{
return (!hasLeftChild(node) && !hasRightChild(node));
}
bool hasOneChild(TreeNode* &node)
{
return ((hasLeftChild(node)) && !(hasRightChild(node))) || ( !(hasLeftChild(node)) && (hasRightChild(node)) );
}
