void removeFromSubTree(TreeNode* &node,int value)
{
if (node == NULL)
printf("no such an element.");
else if (node -> value == value )
{
if((isLeaf(node))||(hasOneChild(node)))
{
if (isLeaf(node))
{
delete node;
node = NULL;
return;
}
if (hasOneChild(node))
{
if(hasLeftChild(node))
{
TreeNode* tmp = node->left;
delete node;
node = tmp;
}
else
{
TreeNode* tmp = node->right;
delete node;
node = tmp;
}
}
}
else
{
int tmp = popMostLeftValue(node->right);
node->value = tmp;
}
}
else if (value > node->value)
return removeFromSubTree(node->right,value);
else
return removeFromSubTree(node->left,value);
}
/* 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)) );
}
