-/* PSPP - computes sample statistics.
- Copyright (C) 2007 Free Software Foundation, Inc.
+/* PSPP - a program for statistical analysis.
+ Copyright (C) 2007, 2009 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
- This program is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Augmented binary tree (ABT) data structure. */
#endif
#include <libpspp/abt.h>
+#include <libpspp/cast.h>
#include <stdbool.h>
abt_init (struct abt *abt,
abt_compare_func *compare,
abt_reaugment_func *reaugment,
- const void *aux)
+ const void *aux)
{
assert (reaugment != NULL);
abt->root = NULL;
This function may be used only if ABT has a comparison
function. */
struct abt_node *
-abt_insert (struct abt *abt, struct abt_node *node)
+abt_insert (struct abt *abt, struct abt_node *node)
{
node->down[0] = NULL;
node->down[1] = NULL;
node->level = 1;
- if (abt->root == NULL)
+ if (abt->root == NULL)
{
abt->root = node;
node->up = NULL;
abt_reaugmented (abt, node);
}
- else
+ else
{
struct abt_node *p = abt->root;
- for (;;)
+ for (;;)
{
int cmp, dir;
break;
}
p = p->down[dir];
- }
+ }
}
- while ((node = node->up) != NULL)
+ while ((node = node->up) != NULL)
{
node = skew (abt, node);
node = split (abt, node);
the tree, if AFTER is true, or the last node, if AFTER is
false. */
static inline void
-insert_relative (struct abt *abt, struct abt_node *p, bool after,
+insert_relative (struct abt *abt, const struct abt_node *p, bool after,
struct abt_node *node)
{
node->down[0] = NULL;
node->down[1] = NULL;
node->level = 1;
- if (abt->root == NULL)
+ if (abt->root == NULL)
{
assert (p == NULL);
abt->root = node;
node->up = NULL;
abt_reaugmented (abt, node);
}
- else
+ else
{
int dir = after;
- if (p == NULL)
+ if (p == NULL)
{
p = abt->root;
dir = !after;
}
- while (p->down[dir] != NULL)
+ while (p->down[dir] != NULL)
{
p = p->down[dir];
- dir = !after;
+ dir = !after;
}
- p->down[dir] = node;
- node->up = p;
+ CONST_CAST (struct abt_node *, p)->down[dir] = node;
+ node->up = CONST_CAST (struct abt_node *, p);
abt_reaugmented (abt, node);
}
- while ((node = node->up) != NULL)
+ while ((node = node->up) != NULL)
{
node = skew (abt, node);
node = split (abt, node);
function. */
void
abt_insert_after (struct abt *abt,
- const struct abt_node *p, struct abt_node *node)
+ const struct abt_node *p, struct abt_node *node)
{
assert (abt->compare == NULL);
- insert_relative (abt, (struct abt_node *) p, true, node);
+ insert_relative (abt, p, true, node);
}
/* Inserts NODE before node P in ABT.
function. */
void
abt_insert_before (struct abt *abt,
- const struct abt_node *p, struct abt_node *node)
+ const struct abt_node *p, struct abt_node *node)
{
assert (abt->compare == NULL);
- insert_relative (abt, (struct abt_node *) p, false, node);
+ insert_relative (abt, p, false, node);
}
/* Deletes P from ABT. */
}
/* Returns the node with minimum value in ABT, or a null pointer
- if ABT is empty. */
+ if ABT is empty. */
struct abt_node *
-abt_first (const struct abt *abt)
+abt_first (const struct abt *abt)
{
struct abt_node *p = abt->root;
- if (p != NULL)
+ if (p != NULL)
while (p->down[0] != NULL)
p = p->down[0];
return p;
}
/* Returns the node with maximum value in ABT, or a null pointer
- if ABT is empty. */
+ if ABT is empty. */
struct abt_node *
-abt_last (const struct abt *abt)
+abt_last (const struct abt *abt)
{
struct abt_node *p = abt->root;
- if (p != NULL)
+ if (p != NULL)
while (p->down[1] != NULL)
p = p->down[1];
return p;
{
const struct abt_node *p;
int cmp;
-
+
for (p = abt->root; p != NULL; p = p->down[cmp > 0])
{
cmp = abt->compare (target, p, abt->aux);
if (cmp == 0)
- return (struct abt_node *) p;
+ return CONST_CAST (struct abt_node *, p);
}
-
+
return NULL;
}
Returns a null pointer if P is the maximum node in ABT or if P
is null and ABT is empty. */
struct abt_node *
-abt_next (const struct abt *abt, const struct abt_node *p)
+abt_next (const struct abt *abt, const struct abt_node *p)
{
- if (p == NULL)
+ if (p == NULL)
return abt_first (abt);
else if (p->down[1] == NULL)
{
p = p->down[1];
while (p->down[0] != NULL)
p = p->down[0];
- return (struct abt_node *) p;
+ return CONST_CAST (struct abt_node *, p);
}
}
Returns a null pointer if P is the minimum node in ABT or if P
is null and ABT is empty. */
struct abt_node *
-abt_prev (const struct abt *abt, const struct abt_node *p)
+abt_prev (const struct abt *abt, const struct abt_node *p)
{
- if (p == NULL)
+ if (p == NULL)
return abt_last (abt);
else if (p->down[0] == NULL)
{
p = p->down[0];
while (p->down[1] != NULL)
p = p->down[1];
- return (struct abt_node *) p;
+ return CONST_CAST (struct abt_node *, p);
}
}
affected nodes from the tree, update their values, then
re-insert all of them. */
void
-abt_reaugmented (const struct abt *abt, struct abt_node *p)
+abt_reaugmented (const struct abt *abt, struct abt_node *p)
{
for (; p != NULL; p = p->up)
abt->reaugment (p, p->down[0], p->down[1], abt->aux);
can actually retain its relative position in ABT, e.g. its key
has only been adjusted slightly. Otherwise, it is more
efficient to simply remove P from ABT, change its key, and
- re-insert P.
+ re-insert P.
It is not safe to update more than one node's key, then to
call this function for each node. Instead, update a single
function. If it doesn't, then you probably just want
abt_reaugmented. */
struct abt_node *
-abt_changed (struct abt *abt, struct abt_node *p)
+abt_changed (struct abt *abt, struct abt_node *p)
{
struct abt_node *prev = abt_prev (abt, p);
struct abt_node *next = abt_next (abt, p);
if ((prev != NULL && abt->compare (prev, p, abt->aux) >= 0)
- || (next != NULL && abt->compare (p, next, abt->aux) >= 0))
+ || (next != NULL && abt->compare (p, next, abt->aux) >= 0))
{
abt_delete (abt, p);
return abt_insert (abt, p);
}
- else
+ else
{
abt_reaugmented (abt, p);
- return NULL;
+ return NULL;
}
}
This function may be used only if ABT has a comparison
function. */
void
-abt_moved (struct abt *abt, struct abt_node *p)
+abt_moved (struct abt *abt, struct abt_node *p)
{
- if (p->up != NULL)
+ if (p->up != NULL)
{
int d = p->up->down[0] == NULL || abt->compare (p, p->up, abt->aux) > 0;
- p->up->down[d] = p;
+ p->up->down[d] = p;
}
else
abt->root = p;
/* Returns the address of the pointer that points down to P
within ABT. */
static struct abt_node **
-down_link (struct abt *abt, struct abt_node *p)
+down_link (struct abt *abt, struct abt_node *p)
{
return (p->up != NULL
? &p->up->down[p->up->down[0] != p]