--- /dev/null
+static char rcsid[]="$Id: redblack.c,v 1.1 2004/03/07 22:02:43 bdemsky Exp $";
+
+/*
+ Redblack balanced tree algorithm
+ Copyright (C) Damian Ivereigh 2000
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version. See the file COPYING for 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 Lesser General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/* Implement the red/black tree structure. It is designed to emulate
+** the standard tsearch() stuff. i.e. the calling conventions are
+** exactly the same
+*/
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "redblack.h"
+
+#define assert(expr)
+#define RB_TRUE 1
+#define RB_FALSE 0
+
+/* Uncomment this if you would rather use a raw sbrk to get memory
+** (however the memory is never released again (only re-used). Can't
+** see any point in using this these days.
+*/
+/* #define USE_SBRK */
+
+enum nodecolour { BLACK, RED };
+
+struct rbnode {
+ struct rbnode *left; /* Left down */
+ struct rbnode *right; /* Right down */
+ struct rbnode *up; /* Up */
+ enum nodecolour colour; /* Node colour */
+ const void *key; /* Pointer to user's key (and data) */
+ const void *high;
+ const void *max;
+ void *object;
+};
+
+/* Dummy (sentinel) node, so that we can make X->left->up = X
+** We then use this instead of NULL to mean the top or bottom
+** end of the rb tree. It is a black node.
+*/
+struct rbnode rb_null={&rb_null, &rb_null, &rb_null, BLACK, NULL,NULL,NULL,NULL};
+#define RBNULL (&rb_null)
+
+#if defined(USE_SBRK)
+
+static struct rbnode *rb_alloc();
+static void rb_free(struct rbnode *);
+
+#else
+
+#define rb_alloc() ((struct rbnode *) malloc(sizeof(struct rbnode)))
+#define rb_free(x) (free(x))
+
+#endif
+
+static struct rbnode *rb_traverse(const void *, struct rbtree *);
+static struct rbnode *rb_lookup(const void *low,const void *high, struct rbtree *);
+static void rb_destroy(struct rbnode *,void (*)(void *));
+static void rb_left_rotate(struct rbnode **, struct rbnode *);
+static void rb_right_rotate(struct rbnode **, struct rbnode *);
+static void rb_delete(struct rbnode **, struct rbnode *);
+static void rb_delete_fix(struct rbnode **, struct rbnode *);
+static struct rbnode *rb_successor(const struct rbnode *);
+static struct rbnode *rb_preccessor(const struct rbnode *);
+static void rb_walk(const struct rbnode *, void (*)(const void *, const VISIT, const int, void *), void *, int);
+static RBLIST *rb_openlist(const struct rbnode *);
+static const void *rb_readlist(RBLIST *);
+static void rb_closelist(RBLIST *);
+
+/*
+** OK here we go, the balanced tree stuff. The algorithm is the
+** fairly standard red/black taken from "Introduction to Algorithms"
+** by Cormen, Leiserson & Rivest. Maybe one of these days I will
+** fully understand all this stuff.
+**
+** Basically a red/black balanced tree has the following properties:-
+** 1) Every node is either red or black (colour is RED or BLACK)
+** 2) A leaf (RBNULL pointer) is considered black
+** 3) If a node is red then its children are black
+** 4) Every path from a node to a leaf contains the same no
+** of black nodes
+**
+** 3) & 4) above guarantee that the longest path (alternating
+** red and black nodes) is only twice as long as the shortest
+** path (all black nodes). Thus the tree remains fairly balanced.
+*/
+
+/*
+ * Initialise a tree. Identifies the comparison routine and any config
+ * data that must be sent to it when called.
+ * Returns a pointer to the top of the tree.
+ */
+struct rbtree * rbinit() {
+ struct rbtree *retval;
+ char c;
+
+ c=rcsid[0]; /* This does nothing but shutup the -Wall */
+
+ if ((retval=(struct rbtree *) malloc(sizeof(struct rbtree)))==NULL)
+ return(NULL);
+
+ retval->rb_root=RBNULL;
+
+ return(retval);
+}
+
+void rbdestroy(struct rbtree *rbinfo, void (*free_function)(void *)) {
+ if (rbinfo==NULL)
+ return;
+
+ if (rbinfo->rb_root!=RBNULL)
+ rb_destroy(rbinfo->rb_root,free_function);
+
+ free(rbinfo);
+}
+
+const void * rbdelete(const void *key, struct rbtree *rbinfo) {
+ struct rbnode *x;
+ const void *y;
+
+ if (rbinfo==NULL)
+ return(NULL);
+
+ x=rb_traverse(key, rbinfo);
+
+ if (x==RBNULL) {
+ return(NULL);
+ } else {
+ y=x->key;
+ rb_delete(&rbinfo->rb_root, x);
+
+ return(y);
+ }
+}
+
+void rbwalk(const struct rbtree *rbinfo, void (*action)(const void *, const VISIT, const int, void *), void *arg) {
+ if (rbinfo==NULL)
+ return;
+
+ rb_walk(rbinfo->rb_root, action, arg, 0);
+}
+
+RBLIST * rbopenlist(const struct rbtree *rbinfo) {
+ if (rbinfo==NULL)
+ return(NULL);
+
+ return(rb_openlist(rbinfo->rb_root));
+}
+
+const void * rbreadlist(RBLIST *rblistp) {
+ if (rblistp==NULL)
+ return(NULL);
+
+ return(rb_readlist(rblistp));
+}
+
+void rbcloselist(RBLIST *rblistp) {
+ if (rblistp==NULL)
+ return;
+
+ rb_closelist(rblistp);
+}
+
+void * rblookup(const void *low,const void *high, struct rbtree *rbinfo) {
+ struct rbnode *x;
+
+ /* If we have a NULL root (empty tree) then just return NULL */
+ if (rbinfo==NULL || rbinfo->rb_root==NULL)
+ return(NULL);
+
+ x=rb_lookup(low, high, rbinfo);
+
+ return((x==RBNULL) ? NULL : x->object);
+}
+
+struct pair rbfind(const void *low,const void *high, struct rbtree *rbinfo) {
+ struct rbnode *x;
+ struct pair p;
+ /* If we have a NULL root (empty tree) then just return NULL */
+
+ p.low=NULL;
+ p.high=NULL;
+ if (rbinfo==NULL || rbinfo->rb_root==NULL)
+ return p;
+
+ x=rb_lookup(low, high, rbinfo);
+ if (x!=NULL) {
+ p.low=x->key;
+ p.high=x->high;
+ }
+ return p;
+}
+
+
+/* --------------------------------------------------------------------- */
+
+/* Search for and if not found and insert is true, will add a new
+** node in. Returns a pointer to the new node, or the node found
+*/
+int rbinsert(const void *key, const void * high, void *object,struct rbtree *rbinfo) {
+ struct rbnode *x,*y,*z, *tmp;
+ const void *max;
+ int found=0;
+
+ y=RBNULL; /* points to the parent of x */
+ x=rbinfo->rb_root;
+
+ /* walk x down the tree */
+ while(x!=RBNULL && found==0) {
+ y=x;
+ /* printf("key=%s, x->key=%s\n", key, x->key); */
+
+ if (key<x->key)
+ x=x->left;
+ else if (key>x->key)
+ x=x->right;
+ else
+ found=1;
+ }
+
+ if (found)
+ return RB_FALSE;
+
+ if ((z=rb_alloc())==NULL) {
+ /* Whoops, no memory */
+ return RB_FALSE;
+ }
+
+ z->object=object;
+ z->high=high;
+ z->key=key;
+ z->max=high;
+ z->up=y;
+ tmp=y;
+ max=high;
+ while(tmp!=RBNULL) {
+ if (max>tmp->max)
+ tmp->max=max;
+ else
+ max=tmp->max;
+ tmp=tmp->up;
+ }
+
+ if (y==RBNULL) {
+ rbinfo->rb_root=z;
+ } else {
+ if (z->key<y->key)
+ y->left=z;
+ else
+ y->right=z;
+ }
+
+ z->left=RBNULL;
+ z->right=RBNULL;
+
+ /* colour this new node red */
+ z->colour=RED;
+
+ /* Having added a red node, we must now walk back up the tree balancing
+ ** it, by a series of rotations and changing of colours
+ */
+ x=z;
+
+ /* While we are not at the top and our parent node is red
+ ** N.B. Since the root node is garanteed black, then we
+ ** are also going to stop if we are the child of the root
+ */
+
+ while(x != rbinfo->rb_root && (x->up->colour == RED)) {
+ /* if our parent is on the left side of our grandparent */
+ if (x->up == x->up->up->left) {
+ /* get the right side of our grandparent (uncle?) */
+ y=x->up->up->right;
+ if (y->colour == RED) {
+ /* make our parent black */
+ x->up->colour = BLACK;
+ /* make our uncle black */
+ y->colour = BLACK;
+ /* make our grandparent red */
+ x->up->up->colour = RED;
+
+ /* now consider our grandparent */
+ x=x->up->up;
+ } else {
+ /* if we are on the right side of our parent */
+ if (x == x->up->right) {
+ /* Move up to our parent */
+ x=x->up;
+ rb_left_rotate(&rbinfo->rb_root, x);
+ }
+
+ /* make our parent black */
+ x->up->colour = BLACK;
+ /* make our grandparent red */
+ x->up->up->colour = RED;
+ /* right rotate our grandparent */
+ rb_right_rotate(&rbinfo->rb_root, x->up->up);
+ }
+ } else {
+ /* everything here is the same as above, but
+ ** exchanging left for right
+ */
+
+ y=x->up->up->left;
+ if (y->colour == RED) {
+ x->up->colour = BLACK;
+ y->colour = BLACK;
+ x->up->up->colour = RED;
+
+ x=x->up->up;
+ } else {
+ if (x == x->up->left) {
+ x=x->up;
+ rb_right_rotate(&rbinfo->rb_root, x);
+ }
+
+ x->up->colour = BLACK;
+ x->up->up->colour = RED;
+ rb_left_rotate(&rbinfo->rb_root, x->up->up);
+ }
+ }
+ }
+
+ /* Set the root node black */
+ (rbinfo->rb_root)->colour = BLACK;
+
+ return RB_TRUE;
+}
+
+/* Search for and if not found and insert is true, will add a new
+** node in. Returns a pointer to the new node, or the node found
+*/
+static struct rbnode * rb_traverse(const void *key, struct rbtree *rbinfo) {
+ struct rbnode *x,*y,*z;
+ int found=0;
+
+ y=RBNULL; /* points to the parent of x */
+ x=rbinfo->rb_root;
+
+ /* walk x down the tree */
+ while(x!=RBNULL && found==0) {
+ y=x;
+ if (key<x->key)
+ x=x->left;
+ else if (key>x->key)
+ x=x->right;
+ else
+ found=1;
+ }
+
+ if (found)
+ return(x);
+ return NULL;
+}
+
+/* Search for a key according (see redblack.h)
+*/
+static struct rbnode * rb_lookup(const void *low, const void *high, struct rbtree *rbinfo) {
+ struct rbnode *x;
+
+ x=rbinfo->rb_root;
+
+ /* walk x down the tree */
+ while(x!=RBNULL) {
+ if (low<x->high &&
+ x->key<high)
+ return x;
+ if (x->left!=RBNULL && x->left->max>low)
+ x=x->left;
+ else
+ x=x->right;
+ }
+
+ return(RBNULL);
+}
+
+/* Search for a key according (see redblack.h)
+*/
+int rbsearch(const void *low, const void *high, struct rbtree *rbinfo) {
+ struct rbnode *x;
+ if (rbinfo==NULL)
+ return RB_FALSE;
+
+ x=rbinfo->rb_root;
+
+ /* walk x down the tree */
+ while(x!=RBNULL) {
+ if (low<x->high &&
+ x->key<high)
+ return RB_TRUE;
+ if (x->left!=RBNULL && x->left->max>low)
+ x=x->left;
+ else
+ x=x->right;
+ }
+
+ return RB_FALSE;
+}
+
+/*
+ * Destroy all the elements blow us in the tree
+ * only useful as part of a complete tree destroy.
+ */
+static void rb_destroy(struct rbnode *x,void (*free_function)(void *)) {
+ if (x!=RBNULL) {
+ if (x->left!=RBNULL)
+ rb_destroy(x->left,free_function);
+ if (x->right!=RBNULL)
+ rb_destroy(x->right,free_function);
+ if (free_function!=NULL)
+ free_function(x->object);
+ rb_free(x);
+ }
+}
+
+/*
+** Rotate our tree thus:-
+**
+** X rb_left_rotate(X)---> Y
+** / \ / \
+** A Y <---rb_right_rotate(Y) X C
+** / \ / \
+** B C A B
+**
+** N.B. This does not change the ordering.
+**
+** We assume that neither X or Y is NULL
+*/
+
+static void rb_left_rotate(struct rbnode **rootp, struct rbnode *x) {
+ struct rbnode *y;
+ const void *max;
+ assert(x!=RBNULL);
+ assert(x->right!=RBNULL);
+
+ y=x->right; /* set Y */
+
+ /* Turn Y's left subtree into X's right subtree (move B)*/
+ x->right = y->left;
+
+ /* If B is not null, set it's parent to be X */
+ if (y->left != RBNULL)
+ y->left->up = x;
+
+ /* Set Y's parent to be what X's parent was */
+ y->up = x->up;
+
+ /* if X was the root */
+ if (x->up == RBNULL) {
+ *rootp=y;
+ } else {
+ /* Set X's parent's left or right pointer to be Y */
+ if (x == x->up->left) {
+ x->up->left=y;
+ } else {
+ x->up->right=y;
+ }
+ }
+
+ /* Put X on Y's left */
+ y->left=x;
+
+ /* Set X's parent to be Y */
+ x->up = y;
+
+ y->max=x->max; /* compute Y's max */
+ max=NULL;
+
+ if (x->left!=RBNULL)
+ max=x->left->max;
+
+ if (x->right!=RBNULL&&
+ x->right->max>max)
+ max=x->right->max;
+ if (x->high>max)
+ max=x->high;
+ x->max=max;
+}
+
+static void rb_right_rotate(struct rbnode **rootp, struct rbnode *y) {
+ struct rbnode *x;
+ const void *max;
+
+ assert(y!=RBNULL);
+ assert(y->left!=RBNULL);
+
+ x=y->left; /* set X */
+
+ /* Turn X's right subtree into Y's left subtree (move B) */
+ y->left = x->right;
+
+ /* If B is not null, set it's parent to be Y */
+ if (x->right != RBNULL)
+ x->right->up = y;
+
+ /* Set X's parent to be what Y's parent was */
+ x->up = y->up;
+
+ /* if Y was the root */
+ if (y->up == RBNULL) {
+ *rootp=x;
+ } else {
+ /* Set Y's parent's left or right pointer to be X */
+ if (y == y->up->left) {
+ y->up->left=x;
+ } else {
+ y->up->right=x;
+ }
+ }
+
+ /* Put Y on X's right */
+ x->right=y;
+
+ /* Set Y's parent to be X */
+ y->up = x;
+
+ x->max=y->max; /* compute Y's max */
+ max=NULL;
+
+ if (y->left!=RBNULL)
+ max=y->left->max;
+
+ if (y->right!=RBNULL&&
+ y->right->max>max)
+ max=y->right->max;
+ if (y->high>max)
+ max=y->high;
+ y->max=max;
+}
+
+/* Return a pointer to the smallest key greater than x
+*/
+static struct rbnode * rb_successor(const struct rbnode *x) {
+ struct rbnode *y;
+
+ if (x->right!=RBNULL) {
+ /* If right is not NULL then go right one and
+ ** then keep going left until we find a node with
+ ** no left pointer.
+ */
+ for (y=x->right; y->left!=RBNULL; y=y->left);
+ } else {
+ /* Go up the tree until we get to a node that is on the
+ ** left of its parent (or the root) and then return the
+ ** parent.
+ */
+ y=x->up;
+ while(y!=RBNULL && x==y->right) {
+ x=y;
+ y=y->up;
+ }
+ }
+ return(y);
+}
+
+/* Return a pointer to the largest key smaller than x
+*/
+static struct rbnode * rb_preccessor(const struct rbnode *x) {
+ struct rbnode *y;
+
+ if (x->left!=RBNULL) {
+ /* If left is not NULL then go left one and
+ ** then keep going right until we find a node with
+ ** no right pointer.
+ */
+ for (y=x->left; y->right!=RBNULL; y=y->right);
+ } else {
+ /* Go up the tree until we get to a node that is on the
+ ** right of its parent (or the root) and then return the
+ ** parent.
+ */
+ y=x->up;
+ while(y!=RBNULL && x==y->left) {
+ x=y;
+ y=y->up;
+ }
+ }
+ return(y);
+}
+
+/* Delete the node z, and free up the space
+*/
+static void rb_delete(struct rbnode **rootp, struct rbnode *z) {
+ struct rbnode *x, *y, *tmp;
+ const void *max;
+
+ if (z->left == RBNULL || z->right == RBNULL)
+ y=z;
+ else
+ y=rb_successor(z);
+
+ if (y->left != RBNULL)
+ x=y->left;
+ else
+ x=y->right;
+
+ x->up = y->up;
+
+ if (y->up == RBNULL) {
+ *rootp=x;
+ } else {
+ if (y==y->up->left)
+ y->up->left = x;
+ else
+ y->up->right = x;
+ }
+
+ if (y!=z) {
+ z->key = y->key;
+ z->high=y->high;
+ z->object=y->object;
+ }
+ tmp=y->up;
+ while(tmp!=RBNULL) {
+ max=NULL;
+ if (tmp->left!=RBNULL)
+ max=tmp->left->max;
+ if (tmp->right!=RBNULL&&
+ tmp->right->max>max)
+ max=tmp->right->max;
+ if (tmp->high>max)
+ max=tmp->high;
+ tmp->max=max;
+ tmp=tmp->up;
+ }
+ if (y->colour == BLACK)
+ rb_delete_fix(rootp, x);
+
+ rb_free(y);
+}
+
+/* Restore the reb-black properties after a delete */
+static void rb_delete_fix(struct rbnode **rootp, struct rbnode *x) {
+ struct rbnode *w;
+
+ while (x!=*rootp && x->colour==BLACK) {
+ if (x==x->up->left) {
+ w=x->up->right;
+ if (w->colour==RED) {
+ w->colour=BLACK;
+ x->up->colour=RED;
+ rb_left_rotate(rootp, x->up);
+ w=x->up->right;
+ }
+ if (w->left->colour==BLACK && w->right->colour==BLACK) {
+ w->colour=RED;
+ x=x->up;
+ } else {
+ if (w->right->colour == BLACK) {
+ w->left->colour=BLACK;
+ w->colour=RED;
+ rb_right_rotate(rootp, w);
+ w=x->up->right;
+ }
+ w->colour=x->up->colour;
+ x->up->colour = BLACK;
+ w->right->colour = BLACK;
+ rb_left_rotate(rootp, x->up);
+ x=*rootp;
+ }
+ } else {
+ w=x->up->left;
+ if (w->colour==RED) {
+ w->colour=BLACK;
+ x->up->colour=RED;
+ rb_right_rotate(rootp, x->up);
+ w=x->up->left;
+ }
+ if (w->right->colour==BLACK && w->left->colour==BLACK) {
+ w->colour=RED;
+ x=x->up;
+ } else {
+ if (w->left->colour == BLACK) {
+ w->right->colour=BLACK;
+ w->colour=RED;
+ rb_left_rotate(rootp, w);
+ w=x->up->left;
+ }
+ w->colour=x->up->colour;
+ x->up->colour = BLACK;
+ w->left->colour = BLACK;
+ rb_right_rotate(rootp, x->up);
+ x=*rootp;
+ }
+ }
+ }
+
+ x->colour=BLACK;
+}
+
+static void
+rb_walk(const struct rbnode *x, void (*action)(const void *, const VISIT, const int, void *), void *arg, int level) {
+ if (x==RBNULL)
+ return;
+
+ if (x->left==RBNULL && x->right==RBNULL) {
+ /* leaf */
+ (*action)(x->key, leaf, level, arg);
+ } else {
+ (*action)(x->key, preorder, level, arg);
+
+ rb_walk(x->left, action, arg, level+1);
+
+ (*action)(x->key, postorder, level, arg);
+
+ rb_walk(x->right, action, arg, level+1);
+
+ (*action)(x->key, endorder, level, arg);
+ }
+}
+
+static RBLIST * rb_openlist(const struct rbnode *rootp) {
+ RBLIST *rblistp;
+
+ rblistp=(RBLIST *) malloc(sizeof(RBLIST));
+ if (!rblistp)
+ return(NULL);
+
+ rblistp->rootp=rootp;
+ rblistp->nextp=rootp;
+
+ if (rootp!=RBNULL) {
+ while(rblistp->nextp->left!=RBNULL) {
+ rblistp->nextp=rblistp->nextp->left;
+ }
+ }
+
+ return(rblistp);
+}
+
+static const void * rb_readlist(RBLIST *rblistp) {
+ const void *key=NULL;
+
+ if (rblistp!=NULL && rblistp->nextp!=RBNULL) {
+ key=rblistp->nextp->key;
+ rblistp->nextp=rb_successor(rblistp->nextp);
+ }
+
+ return(key);
+}
+
+static void rb_closelist(RBLIST *rblistp) {
+ if (rblistp)
+ free(rblistp);
+}
+
+#if defined(USE_SBRK)
+/* Allocate space for our nodes, allowing us to get space from
+** sbrk in larger chucks.
+*/
+static struct rbnode *rbfreep=NULL;
+
+#define RBNODEALLOC_CHUNK_SIZE 1000
+static struct rbnode * rb_alloc() {
+ struct rbnode *x;
+ int i;
+
+ if (rbfreep==NULL) {
+ /* must grab some more space */
+ rbfreep=(struct rbnode *) sbrk(sizeof(struct rbnode) * RBNODEALLOC_CHUNK_SIZE);
+
+ if (rbfreep==(struct rbnode *) -1) {
+ return(NULL);
+ }
+
+ /* tie them together in a linked list (use the up pointer) */
+ for (i=0, x=rbfreep; i<RBNODEALLOC_CHUNK_SIZE-1; i++, x++) {
+ x->up = (x+1);
+ }
+ x->up=NULL;
+ }
+
+ x=rbfreep;
+ rbfreep = rbfreep->up;
+ return(x);
+}
+
+/* free (dealloc) an rbnode structure - add it onto the front of the list
+** N.B. rbnode need not have been allocated through rb_alloc()
+*/
+static void rb_free(struct rbnode *x) {
+ x->up=rbfreep;
+ rbfreep=x;
+}
+
+#endif
+
+#if 0
+int rb_check(struct rbnode *rootp) {
+ if (rootp==NULL || rootp==RBNULL)
+ return(0);
+
+ if (rootp->up!=RBNULL) {
+ fprintf(stderr, "Root up pointer not RBNULL");
+ dumptree(rootp, 0);
+ return(1);
+ }
+
+ if (rb_check1(rootp)) {
+ dumptree(rootp, 0);
+ return(1);
+ }
+
+ if (count_black(rootp)==-1)
+ {
+ dumptree(rootp, 0);
+ return(-1);
+ }
+
+ return(0);
+}
+
+int
+rb_check1(struct rbnode *x)
+{
+ if (x->left==NULL || x->right==NULL)
+ {
+ fprintf(stderr, "Left or right is NULL");
+ return(1);
+ }
+
+ if (x->colour==RED)
+ {
+ if (x->left->colour!=BLACK && x->right->colour!=BLACK)
+ {
+ fprintf(stderr, "Children of red node not both black, x=%ld", x);
+ return(1);
+ }
+ }
+
+ if (x->left != RBNULL)
+ {
+ if (x->left->up != x)
+ {
+ fprintf(stderr, "x->left->up != x, x=%ld", x);
+ return(1);
+ }
+
+ if (rb_check1(x->left))
+ return(1);
+ }
+
+ if (x->right != RBNULL)
+ {
+ if (x->right->up != x)
+ {
+ fprintf(stderr, "x->right->up != x, x=%ld", x);
+ return(1);
+ }
+
+ if (rb_check1(x->right))
+ return(1);
+ }
+ return(0);
+}
+
+count_black(struct rbnode *x)
+{
+ int nleft, nright;
+
+ if (x==RBNULL)
+ return(1);
+
+ nleft=count_black(x->left);
+ nright=count_black(x->right);
+
+ if (nleft==-1 || nright==-1)
+ return(-1);
+
+ if (nleft != nright)
+ {
+ fprintf(stderr, "Black count not equal on left & right, x=%ld", x);
+ return(-1);
+ }
+
+ if (x->colour == BLACK)
+ {
+ nleft++;
+ }
+
+ return(nleft);
+}
+
+dumptree(struct rbnode *x, int n)
+{
+ char *prkey();
+
+ if (x!=NULL && x!=RBNULL)
+ {
+ n++;
+ fprintf(stderr, "Tree: %*s %ld: left=%ld, right=%ld, colour=%s, key=%s",
+ n,
+ "",
+ x,
+ x->left,
+ x->right,
+ (x->colour==BLACK) ? "BLACK" : "RED",
+ prkey(x->key));
+
+ dumptree(x->left, n);
+ dumptree(x->right, n);
+ }
+}
+#endif
+
+/*
+ * $Log: redblack.c,v $
+ * Revision 1.1 2004/03/07 22:02:43 bdemsky
+ *
+ *
+ * Still buggy, but getting closer...
+ *
+ * Revision 1.3 2003/06/18 06:06:18 bdemsky
+ *
+ *
+ * Added option to pass in function to free items in the redblack interval tree.
+ *
+ * Revision 1.5 2002/01/30 07:54:53 damo
+ * Fixed up the libtool versioning stuff (finally)
+ * Fixed bug 500600 (not detecting a NULL return from malloc)
+ * Fixed bug 509485 (no longer needs search.h)
+ * Cleaned up debugging section
+ * Allow multiple inclusions of redblack.h
+ * Thanks to Matthias Andree for reporting (and fixing) these
+ *
+ * Revision 1.4 2000/06/06 14:43:43 damo
+ * Added all the rbwalk & rbopenlist stuff. Fixed up malloc instead of sbrk.
+ * Added two new examples
+ *
+ * Revision 1.3 2000/05/24 06:45:27 damo
+ * Converted everything over to using const
+ * Added a new example1.c file to demonstrate the worst case scenario
+ * Minor fixups of the spec file
+ *
+ * Revision 1.2 2000/05/24 06:17:10 damo
+ * Fixed up the License (now the LGPL)
+ *
+ * Revision 1.1 2000/05/24 04:15:53 damo
+ * Initial import of files. Versions are now all over the place. Oh well
+ *
+ */
+
--- /dev/null
+/*
+ * RCS $Id: redblack.h,v 1.1 2004/03/07 22:02:43 bdemsky Exp $
+ */
+
+/*
+ Redblack balanced tree algorithm
+ Copyright (C) Damian Ivereigh 2000
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version. See the file COPYING for 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 Lesser General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/* Header file for redblack.c, should be included by any code that
+** uses redblack.c since it defines the functions
+*/
+
+/* Stop multiple includes */
+#ifndef _REDBLACK_H
+
+/* For rbwalk - pinched from search.h */
+typedef enum {
+ preorder,
+ postorder,
+ endorder,
+ leaf
+} VISIT;
+
+struct rblists {
+ const struct rbnode *rootp;
+ const struct rbnode *nextp;
+};
+
+#define RBLIST struct rblists
+
+struct rbtree {
+ /* root of tree */
+ struct rbnode *rb_root;
+};
+
+struct pair {
+ const void *low,*high;
+};
+
+struct rbtree *rbinit();
+int rbinsert(const void *low, const void * high, void *object,struct rbtree *rbinfo);
+struct pair rbfind(const void *low,const void *high, struct rbtree *rbinfo);
+const void *rbdelete(const void *, struct rbtree *);
+void *rblookup(const void *, const void *,struct rbtree *);
+int rbsearch(const void *low, const void *high, struct rbtree *rbinfo);
+void rbdestroy(struct rbtree *,void (*free_function)(void *));
+void rbwalk(const struct rbtree *,
+ void (*)(const void *, const VISIT, const int, void *),
+ void *);
+RBLIST *rbopenlist(const struct rbtree *);
+const void *rbreadlist(RBLIST *);
+void rbcloselist(RBLIST *);
+
+/* Some useful macros */
+#define rbmin(rbinfo) rblookup(RB_LUFIRST, NULL, (rbinfo))
+#define rbmax(rbinfo) rblookup(RB_LULAST, NULL, (rbinfo))
+
+#define _REDBLACK_H
+#endif /* _REDBLACK_H */
+
+/*
+ *
+ * $Log: redblack.h,v $
+ * Revision 1.1 2004/03/07 22:02:43 bdemsky
+ *
+ *
+ * Still buggy, but getting closer...
+ *
+ * Revision 1.2 2003/06/18 06:06:18 bdemsky
+ *
+ *
+ * Added option to pass in function to free items in the redblack interval tree.
+ *
+ * Revision 1.5 2002/01/30 07:54:53 damo
+ * Fixed up the libtool versioning stuff (finally)
+ * Fixed bug 500600 (not detecting a NULL return from malloc)
+ * Fixed bug 509485 (no longer needs search.h)
+ * Cleaned up debugging section
+ * Allow multiple inclusions of redblack.h
+ * Thanks to Matthias Andree for reporting (and fixing) these
+ *
+ * Revision 1.4 2000/06/06 14:43:43 damo
+ * Added all the rbwalk & rbopenlist stuff. Fixed up malloc instead of sbrk.
+ * Added two new examples
+ *
+ * Revision 1.3 2000/05/24 06:45:27 damo
+ * Converted everything over to using const
+ * Added a new example1.c file to demonstrate the worst case scenario
+ * Minor fixups of the spec file
+ *
+ * Revision 1.2 2000/05/24 06:17:10 damo
+ * Fixed up the License (now the LGPL)
+ *
+ * Revision 1.1 2000/05/24 04:15:53 damo
+ * Initial import of files. Versions are now all over the place. Oh well
+ *
+ */
+
projects / repair.git / commitdiff