pRBNode BSTdelete(pRBNode root, int val, char *col) {
pRBNode tmp;
if(root == NULL)
return root;
else if(val < root->val)
root->left = BSTdelete(root->left, val, col);
else if(val > root->val)
root->right = BSTdelete(root->right, val, col);
else if(root->left && root->right) { // node with two children
tmp = findMin(root->right);
*col = tmp->color; // remember the original color of successor
root->val = tmp->val;
root->right = BSTdelete(root->right, root->val, col);
} else { // node with 0 or 1 child
tmp = root;
*col = tmp->color; // remember the original color of successor
if(root->left == NULL)
root = root->right;
else if(root->right == NULL)
root = root->left;
free(tmp);
}
return root;
}
void inserisci_a_caso(rbtree* p){
int x,y;
x = BSTGetRootX(adm_positions);
y = BSTGetRootY(adm_positions);
rbinsert(p,x,y);
adm_positions = BSTdelete(adm_positions,x,y);
}
void deleteRBNode(ppRBNode root, int val) {
// If z is the node to be deleted, then the original color of z's successor is: original_color
char original_color;
// 1. Perform standard binary-search-tree deletion
pRBNode x = BSTdelete(*root, val, &original_color);
if(x == NULL)
return ;
// 2. Fix the RB-tree if necessary
if(original_color == 'B')
deleteFixup(root, x);
}
/* Inserimento del singolo nodo, con valorizzazione di tutti i campi del nodo */
rbnode *simpleinsert(rbtree *tree, int x, int y)
{
// controlla se la tessera nelle posizioni x, y è ammessa
if (BSTsearch(adm_positions,x,y)!= 1){
return NULL;
}
// cancella la tessera dalle posizioni ammesse
adm_positions = BSTdelete(adm_positions,x,y);
rbnode *q = (rbnode*) malloc(sizeof(rbnode));
rbnode *r = tree->root;
rbnode *s = tree->nil;
if(!q) {
fprintf(stderr,"Errore di allocazione C\n");
exit(-4);
}
q->x = x;
q->y = y;
q->left = q->right = tree->nil;
q->c = red;
while(r != tree->nil) { /* Controllo dove va inserito il nuovo nodo */
s = r;
if (is_lower_than(x,y, r->x, r->y) < 0){
r = r->left;
}
else{
if (is_lower_than(x,y, r->x, r->y) == 0)
return NULL;
r = r->right;
}
}
q->up = s;
if(s == tree->nil)
tree->root = q;
else{
if(is_lower_than(x,y, s->x, s->y) < 0)
s->left = q;
else{
if (is_lower_than(x,y, s->x, s->y) == 0)
return NULL;
s->right = q;
}
}
// aumenta il numero nodi presenti
tree->count=tree->count +1;
// ottiene le posizioni ammissibili del nuovo nodo
int* positions = get_admitted_positions(x,y);
int collisions = 0;
for(size_t i = 0; i < 7; i = i+2 )
{
rbnode *rnode = search(tree,positions[i],positions[i+1]);
if (rnode){
collisions = collisions +1;
}else{
adm_positions = BSTinsert( adm_positions, positions[i],positions[i+1] );
}
}
/// caricamento variabili di utilità
if (x<0 && x< tree->xdown) tree->xdown = x;
if (x>0 && x> tree->xup) tree->xup = x;
if (y<0 && y< tree->ydown) tree->ydown = y;
if (y>0 && y> tree->yup) tree->yup = y;
// generazione del perimetro e dell'ordine
tree->ordine = 1+ MAX(tree->xup - tree->xdown,tree->yup - tree->ydown);
tree->perimetro= (tree->perimetro+4) -(collisions*2);
return q;
}