diff options
Diffstat (limited to 'test/monniaux/glpk-4.65/src/misc/avl.c')
| -rw-r--r-- | test/monniaux/glpk-4.65/src/misc/avl.c | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/test/monniaux/glpk-4.65/src/misc/avl.c b/test/monniaux/glpk-4.65/src/misc/avl.c new file mode 100644 index 00000000..c97cf13a --- /dev/null +++ b/test/monniaux/glpk-4.65/src/misc/avl.c @@ -0,0 +1,405 @@ +/* avl.c (binary search tree) */ + +/*********************************************************************** +* This code is part of GLPK (GNU Linear Programming Kit). +* +* Copyright (C) 2000-2013 Andrew Makhorin, Department for Applied +* Informatics, Moscow Aviation Institute, Moscow, Russia. All rights +* reserved. E-mail: <mao@gnu.org>. +* +* GLPK 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. +* +* GLPK 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 GLPK. If not, see <http://www.gnu.org/licenses/>. +***********************************************************************/ + +#include "avl.h" +#include "dmp.h" +#include "env.h" + +struct AVL +{ /* AVL tree (Adelson-Velsky & Landis binary search tree) */ + DMP *pool; + /* memory pool for allocating nodes */ + AVLNODE *root; + /* pointer to the root node */ + int (*fcmp)(void *info, const void *key1, const void *key2); + /* application-defined key comparison routine */ + void *info; + /* transit pointer passed to the routine fcmp */ + int size; + /* the tree size (the total number of nodes) */ + int height; + /* the tree height */ +}; + +struct AVLNODE +{ /* node of AVL tree */ + const void *key; + /* pointer to the node key (data structure for representing keys + is supplied by the application) */ + int rank; + /* node rank = relative position of the node in its own subtree = + the number of nodes in the left subtree plus one */ + int type; + /* reserved for the application specific information */ + void *link; + /* reserved for the application specific information */ + AVLNODE *up; + /* pointer to the parent node */ + short int flag; + /* node flag: + 0 - this node is the left child of its parent (or this node is + the root of the tree and has no parent) + 1 - this node is the right child of its parent */ + short int bal; + /* node balance = the difference between heights of the right and + left subtrees: + -1 - the left subtree is higher than the right one; + 0 - the left and right subtrees have the same height; + +1 - the left subtree is lower than the right one */ + AVLNODE *left; + /* pointer to the root of the left subtree */ + AVLNODE *right; + /* pointer to the root of the right subtree */ +}; + +AVL *avl_create_tree(int (*fcmp)(void *info, const void *key1, + const void *key2), void *info) +{ /* create AVL tree */ + AVL *tree; + tree = xmalloc(sizeof(AVL)); + tree->pool = dmp_create_pool(); + tree->root = NULL; + tree->fcmp = fcmp; + tree->info = info; + tree->size = 0; + tree->height = 0; + return tree; +} + +int avl_strcmp(void *info, const void *key1, const void *key2) +{ /* compare character string keys */ + xassert(info == info); + return strcmp(key1, key2); +} + +static AVLNODE *rotate_subtree(AVL *tree, AVLNODE *node); + +AVLNODE *avl_insert_node(AVL *tree, const void *key) +{ /* insert new node into AVL tree */ + AVLNODE *p, *q, *r; + short int flag; + /* find an appropriate point for insertion */ + p = NULL; q = tree->root; + while (q != NULL) + { p = q; + if (tree->fcmp(tree->info, key, p->key) <= 0) + { flag = 0; + q = p->left; + p->rank++; + } + else + { flag = 1; + q = p->right; + } + } + /* create new node and insert it into the tree */ + r = dmp_get_atom(tree->pool, sizeof(AVLNODE)); + r->key = key; r->type = 0; r->link = NULL; + r->rank = 1; r->up = p; + r->flag = (short int)(p == NULL ? 0 : flag); + r->bal = 0; r->left = NULL; r->right = NULL; + tree->size++; + if (p == NULL) + tree->root = r; + else + if (flag == 0) p->left = r; else p->right = r; + /* go upstairs to the root and correct all subtrees affected by + insertion */ + while (p != NULL) + { if (flag == 0) + { /* the height of the left subtree of [p] is increased */ + if (p->bal > 0) + { p->bal = 0; + break; + } + if (p->bal < 0) + { rotate_subtree(tree, p); + break; + } + p->bal = -1; flag = p->flag; p = p->up; + } + else + { /* the height of the right subtree of [p] is increased */ + if (p->bal < 0) + { p->bal = 0; + break; + } + if (p->bal > 0) + { rotate_subtree(tree, p); + break; + } + p->bal = +1; flag = p->flag; p = p->up; + } + } + /* if the root has been reached, the height of the entire tree is + increased */ + if (p == NULL) tree->height++; + return r; +} + +void avl_set_node_type(AVLNODE *node, int type) +{ /* assign the type field of specified node */ + node->type = type; + return; +} + +void avl_set_node_link(AVLNODE *node, void *link) +{ /* assign the link field of specified node */ + node->link = link; + return; +} + +AVLNODE *avl_find_node(AVL *tree, const void *key) +{ /* find node in AVL tree */ + AVLNODE *p; + int c; + p = tree->root; + while (p != NULL) + { c = tree->fcmp(tree->info, key, p->key); + if (c == 0) break; + p = (c < 0 ? p->left : p->right); + } + return p; +} + +int avl_get_node_type(AVLNODE *node) +{ /* retrieve the type field of specified node */ + return node->type; +} + +void *avl_get_node_link(AVLNODE *node) +{ /* retrieve the link field of specified node */ + return node->link; +} + +static AVLNODE *find_next_node(AVL *tree, AVLNODE *node) +{ /* find next node in AVL tree */ + AVLNODE *p, *q; + if (tree->root == NULL) return NULL; + p = node; + q = (p == NULL ? tree->root : p->right); + if (q == NULL) + { /* go upstairs from the left subtree */ + for (;;) + { q = p->up; + if (q == NULL) break; + if (p->flag == 0) break; + p = q; + } + } + else + { /* go downstairs into the right subtree */ + for (;;) + { p = q->left; + if (p == NULL) break; + q = p; + } + } + return q; +} + +void avl_delete_node(AVL *tree, AVLNODE *node) +{ /* delete specified node from AVL tree */ + AVLNODE *f, *p, *q, *r, *s, *x, *y; + short int flag; + p = node; + /* if both subtrees of the specified node are non-empty, the node + should be interchanged with the next one, at least one subtree + of which is always empty */ + if (p->left == NULL || p->right == NULL) goto skip; + f = p->up; q = p->left; + r = find_next_node(tree, p); s = r->right; + if (p->right == r) + { if (f == NULL) + tree->root = r; + else + if (p->flag == 0) f->left = r; else f->right = r; + r->rank = p->rank; r->up = f; + r->flag = p->flag; r->bal = p->bal; + r->left = q; r->right = p; + q->up = r; + p->rank = 1; p->up = r; p->flag = 1; + p->bal = (short int)(s == NULL ? 0 : +1); + p->left = NULL; p->right = s; + if (s != NULL) s->up = p; + } + else + { x = p->right; y = r->up; + if (f == NULL) + tree->root = r; + else + if (p->flag == 0) f->left = r; else f->right = r; + r->rank = p->rank; r->up = f; + r->flag = p->flag; r->bal = p->bal; + r->left = q; r->right = x; + q->up = r; x->up = r; y->left = p; + p->rank = 1; p->up = y; p->flag = 0; + p->bal = (short int)(s == NULL ? 0 : +1); + p->left = NULL; p->right = s; + if (s != NULL) s->up = p; + } +skip: /* now the specified node [p] has at least one empty subtree; + go upstairs to the root and adjust the rank field of all nodes + affected by deletion */ + q = p; f = q->up; + while (f != NULL) + { if (q->flag == 0) f->rank--; + q = f; f = q->up; + } + /* delete the specified node from the tree */ + f = p->up; flag = p->flag; + q = p->left != NULL ? p->left : p->right; + if (f == NULL) + tree->root = q; + else + if (flag == 0) f->left = q; else f->right = q; + if (q != NULL) q->up = f, q->flag = flag; + tree->size--; + /* go upstairs to the root and correct all subtrees affected by + deletion */ + while (f != NULL) + { if (flag == 0) + { /* the height of the left subtree of [f] is decreased */ + if (f->bal == 0) + { f->bal = +1; + break; + } + if (f->bal < 0) + f->bal = 0; + else + { f = rotate_subtree(tree, f); + if (f->bal < 0) break; + } + flag = f->flag; f = f->up; + } + else + { /* the height of the right subtree of [f] is decreased */ + if (f->bal == 0) + { f->bal = -1; + break; + } + if (f->bal > 0) + f->bal = 0; + else + { f = rotate_subtree(tree, f); + if (f->bal > 0) break; + } + flag = f->flag; f = f->up; + } + } + /* if the root has been reached, the height of the entire tree is + decreased */ + if (f == NULL) tree->height--; + /* returns the deleted node to the memory pool */ + dmp_free_atom(tree->pool, p, sizeof(AVLNODE)); + return; +} + +static AVLNODE *rotate_subtree(AVL *tree, AVLNODE *node) +{ /* restore balance of AVL subtree */ + AVLNODE *f, *p, *q, *r, *x, *y; + xassert(node != NULL); + p = node; + if (p->bal < 0) + { /* perform negative (left) rotation */ + f = p->up; q = p->left; r = q->right; + if (q->bal <= 0) + { /* perform single negative rotation */ + if (f == NULL) + tree->root = q; + else + if (p->flag == 0) f->left = q; else f->right = q; + p->rank -= q->rank; + q->up = f; q->flag = p->flag; q->bal++; q->right = p; + p->up = q; p->flag = 1; + p->bal = (short int)(-q->bal); p->left = r; + if (r != NULL) r->up = p, r->flag = 0; + node = q; + } + else + { /* perform double negative rotation */ + x = r->left; y = r->right; + if (f == NULL) + tree->root = r; + else + if (p->flag == 0) f->left = r; else f->right = r; + p->rank -= (q->rank + r->rank); + r->rank += q->rank; + p->bal = (short int)(r->bal >= 0 ? 0 : +1); + q->bal = (short int)(r->bal <= 0 ? 0 : -1); + r->up = f; r->flag = p->flag; r->bal = 0; + r->left = q; r->right = p; + p->up = r; p->flag = 1; p->left = y; + q->up = r; q->flag = 0; q->right = x; + if (x != NULL) x->up = q, x->flag = 1; + if (y != NULL) y->up = p, y->flag = 0; + node = r; + } + } + else + { /* perform positive (right) rotation */ + f = p->up; q = p->right; r = q->left; + if (q->bal >= 0) + { /* perform single positive rotation */ + if (f == NULL) + tree->root = q; + else + if (p->flag == 0) f->left = q; else f->right = q; + q->rank += p->rank; + q->up = f; q->flag = p->flag; q->bal--; q->left = p; + p->up = q; p->flag = 0; + p->bal = (short int)(-q->bal); p->right = r; + if (r != NULL) r->up = p, r->flag = 1; + node = q; + } + else + { /* perform double positive rotation */ + x = r->left; y = r->right; + if (f == NULL) + tree->root = r; + else + if (p->flag == 0) f->left = r; else f->right = r; + q->rank -= r->rank; + r->rank += p->rank; + p->bal = (short int)(r->bal <= 0 ? 0 : -1); + q->bal = (short int)(r->bal >= 0 ? 0 : +1); + r->up = f; r->flag = p->flag; r->bal = 0; + r->left = p; r->right = q; + p->up = r; p->flag = 0; p->right = x; + q->up = r; q->flag = 1; q->left = y; + if (x != NULL) x->up = p, x->flag = 1; + if (y != NULL) y->up = q, y->flag = 0; + node = r; + } + } + return node; +} + +void avl_delete_tree(AVL *tree) +{ /* delete AVL tree */ + dmp_delete_pool(tree->pool); + xfree(tree); + return; +} + +/* eof */ |