/*
* removal
*/
int
AVLTree::Remove (AVLTree * &racine, bool rebalance)
{
AVLTree *startNode = NULL;
int remDiff = 0;
int res = Remove (racine, startNode, remDiff);
if (res == avl_no_err && rebalance && startNode)
res = startNode->RestoreBalances (remDiff, racine);
return res;
}
int
AVLTree::RestoreBalances (int diff, AVLTree * &racine)
{
if (balance > 0)
{
if (diff < 0)
{
balance = 0;
if (parent)
{
if (this == parent->child[RIGHT])
return parent->RestoreBalances (1, racine);
if (this == parent->child[LEFT])
return parent->RestoreBalances (-1, racine);
}
return avl_no_err;
}
else if (diff == 0)
{
}
else if (diff > 0)
{
if (child[LEFT] == NULL)
{
// cout << "un probleme\n";
return avl_bal_err;
}
AVLTree *r = parent;
AVLTree *a = this;
AVLTree *b = child[RIGHT];
AVLTree *e = child[LEFT];
AVLTree *f = e->child[RIGHT];
AVLTree *g = e->child[LEFT];
if (e->balance > 0)
{
e->child[RIGHT] = a;
e->child[LEFT] = g;
a->child[RIGHT] = b;
a->child[LEFT] = f;
if (a)
a->parent = e;
if (g)
g->parent = e;
if (b)
b->parent = a;
if (f)
f->parent = a;
e->parent = r;
if (r)
{
if (r->child[LEFT] == a)
r->child[LEFT] = e;
if (r->child[RIGHT] == a)
r->child[RIGHT] = e;
}
if (racine == this)
racine = e;
e->balance = 0;
a->balance = 0;
if (r)
{
if (e == r->child[RIGHT])
return r->RestoreBalances (1, racine);
if (e == r->child[LEFT])
return r->RestoreBalances (-1, racine);
}
return avl_no_err;
}
else if (e->balance == 0)
{
e->child[RIGHT] = a;
e->child[LEFT] = g;
a->child[RIGHT] = b;
a->child[LEFT] = f;
if (a)
a->parent = e;
if (g)
g->parent = e;
if (b)
b->parent = a;
if (f)
f->parent = a;
e->parent = r;
if (r)
{
if (r->child[LEFT] == a)
r->child[LEFT] = e;
if (r->child[RIGHT] == a)
r->child[RIGHT] = e;
}
if (racine == this)
racine = e;
e->balance = -1;
a->balance = 1;
return avl_no_err;
}
else if (e->balance < 0)
{
if (child[LEFT]->child[RIGHT] == NULL)
{
// cout << "un probleme\n";
return avl_bal_err;
}
AVLTree *i = child[LEFT]->child[RIGHT]->child[RIGHT];
AVLTree *j = child[LEFT]->child[RIGHT]->child[LEFT];
f->child[RIGHT] = a;
f->child[LEFT] = e;
a->child[RIGHT] = b;
a->child[LEFT] = i;
e->child[RIGHT] = j;
e->child[LEFT] = g;
if (b)
b->parent = a;
if (i)
i->parent = a;
if (g)
g->parent = e;
if (j)
j->parent = e;
if (a)
a->parent = f;
if (e)
e->parent = f;
f->parent = r;
if (r)
{
if (r->child[LEFT] == a)
r->child[LEFT] = f;
if (r->child[RIGHT] == a)
r->child[RIGHT] = f;
}
if (racine == this)
racine = f;
int oBal = f->balance;
f->balance = 0;
if (oBal > 0)
{
a->balance = -1;
e->balance = 0;
}
else if (oBal == 0)
{
a->balance = 0;
e->balance = 0;
}
else if (oBal < 0)
{
a->balance = 0;
e->balance = 1;
}
if (r)
{
if (f == r->child[RIGHT])
return r->RestoreBalances (1, racine);
if (f == r->child[LEFT])
return r->RestoreBalances (-1, racine);
}
return avl_no_err;
}
}
}
else if (balance == 0)
{
if (diff < 0)
{
balance = -1;
}
else if (diff == 0)
{
}
else if (diff > 0)
{
balance = 1;
}
return avl_no_err;
}
else if (balance < 0)
{
if (diff < 0)
{
if (child[RIGHT] == NULL)
{
// cout << "un probleme\n";
return avl_bal_err;
}
AVLTree *r = parent;
AVLTree *a = this;
AVLTree *b = child[LEFT];
AVLTree *e = child[RIGHT];
AVLTree *f = e->child[LEFT];
AVLTree *g = e->child[RIGHT];
if (e->balance < 0)
{
e->child[LEFT] = a;
e->child[RIGHT] = g;
a->child[LEFT] = b;
a->child[RIGHT] = f;
if (a)
a->parent = e;
if (g)
g->parent = e;
if (b)
b->parent = a;
if (f)
f->parent = a;
e->parent = r;
if (r)
{
if (r->child[LEFT] == a)
r->child[LEFT] = e;
if (r->child[RIGHT] == a)
r->child[RIGHT] = e;
}
if (racine == this)
racine = e;
e->balance = 0;
a->balance = 0;
if (r)
{
if (e == r->child[RIGHT])
return r->RestoreBalances (1, racine);
if (e == r->child[LEFT])
return r->RestoreBalances (-1, racine);
}
return avl_no_err;
}
else if (e->balance == 0)
{
e->child[LEFT] = a;
e->child[RIGHT] = g;
a->child[LEFT] = b;
a->child[RIGHT] = f;
if (a)
a->parent = e;
if (g)
g->parent = e;
if (b)
b->parent = a;
if (f)
f->parent = a;
e->parent = r;
if (r)
{
if (r->child[LEFT] == a)
r->child[LEFT] = e;
if (r->child[RIGHT] == a)
r->child[RIGHT] = e;
}
if (racine == this)
racine = e;
e->balance = 1;
a->balance = -1;
return avl_no_err;
}
else if (e->balance > 0)
{
if (child[RIGHT]->child[LEFT] == NULL)
{
// cout << "un probleme\n";
return avl_bal_err;
}
AVLTree *i = child[RIGHT]->child[LEFT]->child[LEFT];
AVLTree *j = child[RIGHT]->child[LEFT]->child[RIGHT];
f->child[LEFT] = a;
f->child[RIGHT] = e;
a->child[LEFT] = b;
a->child[RIGHT] = i;
e->child[LEFT] = j;
e->child[RIGHT] = g;
if (b)
b->parent = a;
if (i)
i->parent = a;
if (g)
g->parent = e;
if (j)
j->parent = e;
if (a)
a->parent = f;
if (e)
e->parent = f;
f->parent = r;
if (r)
{
if (r->child[LEFT] == a)
r->child[LEFT] = f;
if (r->child[RIGHT] == a)
r->child[RIGHT] = f;
}
if (racine == this)
racine = f;
int oBal = f->balance;
f->balance = 0;
if (oBal > 0)
{
a->balance = 0;
e->balance = -1;
}
else if (oBal == 0)
{
a->balance = 0;
e->balance = 0;
}
else if (oBal < 0)
{
a->balance = 1;
e->balance = 0;
}
if (r)
{
if (f == r->child[RIGHT])
return r->RestoreBalances (1, racine);
if (f == r->child[LEFT])
return r->RestoreBalances (-1, racine);
}
return avl_no_err;
}
}
else if (diff == 0)
{
}
else if (diff > 0)
{
balance = 0;
if (parent)
{
if (this == parent->child[RIGHT])
return parent->RestoreBalances (1, racine);
if (this == parent->child[LEFT])
return parent->RestoreBalances (-1, racine);
}
return avl_no_err;
}
}
return avl_no_err;
}