del(int item)
{
struct node *parent,*location;
if(root==NULL)
{
printf("\ntree empty\n");
return;
}
find(item,&parent,&location);
if(location==NULL)
{
printf("\nitem is not present in tree\n");
return;
}
if((location->lchild==NULL)&&(location->rchild==NULL))
case_a(parent,location);
if((location->lchild!=NULL)&&(location->rchild==NULL))
case_b(parent,location);
if((location->lchild==NULL)&&(location->rchild!=NULL))
case_b(parent,location);
if((location->lchild!=NULL)&&(location->rchild!=NULL))
case_c(parent,location);
free(location);
printf("\ndeleted\n");
}
case_c(struct node *par,struct node *loc)
{
struct node *parsuc,*suc;
parsuc=loc;
suc=loc->rchild;
while(suc->lchild!=NULL)
{
parsuc=suc;
suc=suc->lchild;
}
if((suc->lchild==NULL)&&(suc->rchild==NULL))
case_a(parsuc,suc);
else
case_b(parsuc,suc);
if(par==NULL)
root=suc;
else
{
if(loc==par->lchild)
par->lchild=suc;
else
par->rchild=suc;
}
suc->lchild=loc->lchild;
suc->rchild=loc->rchild;
}
void BinTree::del(int key) {
tree_node *parent, *location;
if (root == NULL) {
std::cout << "Tree empty" << std::endl;
return;
}
find(key, &parent, &location);
if (location == NULL) {
std::cout << "Item not present in tree" << std::endl;
return;
}
if (location->left == NULL && location->right == NULL) {
case_a(parent, location);
}
if (location->left != NULL && location->right == NULL) {
case_b(parent, location);
}
if (location->left == NULL && location->right != NULL) {
case_b(parent, location);
}
if (location->left != NULL && location->right != NULL) {
case_c(parent, location);
}
delete location;
}
void BinTree::case_c(tree_node *par, tree_node *loc) {
tree_node *ptr, *ptrsave, *suc, *parsuc;
ptrsave = loc;
ptr = loc->right;
while (ptr->left != NULL) {
ptrsave = ptr;
ptr = ptr->left;
}
suc = ptr;
parsuc = ptrsave;
if (suc->left == NULL && suc->right == NULL) {
case_a(parsuc, suc);
} else {
case_b(parsuc, suc);
}
if (par == NULL) {
root = suc;
} else {
if (loc == par->left) {
par->left = suc;
} else {
par->right = suc;
}
}
suc->left = loc->left;
suc->right = loc->right;
}
case_c(struct node *par,struct node *loc)
{
struct node *ptr,*ptrsave,*suc,*parsuc;
/*Find inorder successor and its parent*/
ptrsave=loc;
ptr=loc->rchild;
while(ptr->lchild!=NULL)
{
ptrsave=ptr;
ptr=ptr->lchild;
}
suc=ptr;
parsuc=ptrsave;
if(suc->lchild==NULL && suc->rchild==NULL)
case_a(parsuc,suc);
else
case_b(parsuc,suc);
if(par==NULL) /*if item to be deleted is root node */
root=suc;
else
if(loc==par->lchild)
par->lchild=suc;
else
par->rchild=suc;
suc->lchild=loc->lchild;
suc->rchild=loc->rchild;
}/*End of case_c()*/
del(int item)
{
struct node *parent,*location;
if(root==NULL)
{
printf("Tree empty");
return;
}
find(item,&parent,&location);
if(location==NULL)
{
printf("Item not present in tree");
return;
}
if(location->lchild==NULL && location->rchild==NULL)
case_a(parent,location);
if(location->lchild!=NULL && location->rchild==NULL)
case_b(parent,location);
if(location->lchild==NULL && location->rchild!=NULL)
case_b(parent,location);
if(location->lchild!=NULL && location->rchild!=NULL)
case_c(parent,location);
free(location);
}/*End of del()*/
void del(int item)
{
if(head==NULL)
{
printf("Tree empty");
return;
}
find(item);
if(Loc==NULL)
{
printf("Item not present in tree");
return;
}
if(Loc->left==thread && Loc->right==thread) // for zero child
case_a(head,Par,Loc);
if(Loc->left==link && Loc->right==thread) // for one left child
case_b(head,Par,Loc);
if(Loc->left==thread && Loc->right==link) // for one right child
case_b(head,Par,Loc);
if(Loc->left==link && Loc->right==link) // for two child left and right
case_c(head,Par,Loc);
}
case_c( node *head,node *Par,node *Loc)
{
node *ptr,*ptrsave,*suc,*parsuc;
/*Find inorder successor and its parent*/
ptrsave=Loc;
ptr=Loc->right_ptr;
while(ptr->left==link)
{
ptrsave=ptr;
ptr=ptr->left_ptr;
}
suc=ptr;
parsuc=ptrsave;
Loc->data= suc->data;
if(suc->left==thread && suc->right==thread)
case_a(head,parsuc,suc);
else
case_b(head,parsuc,suc);
}
