Benny Prijono | 9033e31 | 2005-11-21 02:08:39 +0000 | [diff] [blame] | 1 | /* $Id$ */ |
| 2 | /* |
| 3 | * Copyright (C)2003-2006 Benny Prijono <benny@prijono.org> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 | */ |
| 19 | #include <pj/rbtree.h> |
| 20 | #include <pj/os.h> |
| 21 | |
| 22 | static void left_rotate( pj_rbtree *tree, pj_rbtree_node *node ) |
| 23 | { |
| 24 | pj_rbtree_node *rnode, *parent; |
| 25 | |
| 26 | PJ_CHECK_STACK(); |
| 27 | |
| 28 | rnode = node->right; |
| 29 | if (rnode == tree->null) |
| 30 | return; |
| 31 | |
| 32 | node->right = rnode->left; |
| 33 | if (rnode->left != tree->null) |
| 34 | rnode->left->parent = node; |
| 35 | parent = node->parent; |
| 36 | rnode->parent = parent; |
| 37 | if (parent != tree->null) { |
| 38 | if (parent->left == node) |
| 39 | parent->left = rnode; |
| 40 | else |
| 41 | parent->right = rnode; |
| 42 | } else { |
| 43 | tree->root = rnode; |
| 44 | } |
| 45 | rnode->left = node; |
| 46 | node->parent = rnode; |
| 47 | } |
| 48 | |
| 49 | static void right_rotate( pj_rbtree *tree, pj_rbtree_node *node ) |
| 50 | { |
| 51 | pj_rbtree_node *lnode, *parent; |
| 52 | |
| 53 | PJ_CHECK_STACK(); |
| 54 | |
| 55 | lnode = node->left; |
| 56 | if (lnode == tree->null) |
| 57 | return; |
| 58 | |
| 59 | node->left = lnode->right; |
| 60 | if (lnode->right != tree->null) |
| 61 | lnode->right->parent = node; |
| 62 | parent = node->parent; |
| 63 | lnode->parent = parent; |
| 64 | |
| 65 | if (parent != tree->null) { |
| 66 | if (parent->left == node) |
| 67 | parent->left = lnode; |
| 68 | else |
| 69 | parent->right = lnode; |
| 70 | } else { |
| 71 | tree->root = lnode; |
| 72 | } |
| 73 | lnode->right = node; |
| 74 | node->parent = lnode; |
| 75 | } |
| 76 | |
| 77 | static void insert_fixup( pj_rbtree *tree, pj_rbtree_node *node ) |
| 78 | { |
| 79 | pj_rbtree_node *temp, *parent; |
| 80 | |
| 81 | PJ_CHECK_STACK(); |
| 82 | |
| 83 | while (node != tree->root && node->parent->color == PJ_RBCOLOR_RED) { |
| 84 | parent = node->parent; |
| 85 | if (parent == parent->parent->left) { |
| 86 | temp = parent->parent->right; |
| 87 | if (temp->color == PJ_RBCOLOR_RED) { |
| 88 | temp->color = PJ_RBCOLOR_BLACK; |
| 89 | node = parent; |
| 90 | node->color = PJ_RBCOLOR_BLACK; |
| 91 | node = node->parent; |
| 92 | node->color = PJ_RBCOLOR_RED; |
| 93 | } else { |
| 94 | if (node == parent->right) { |
| 95 | node = parent; |
| 96 | left_rotate(tree, node); |
| 97 | } |
| 98 | temp = node->parent; |
| 99 | temp->color = PJ_RBCOLOR_BLACK; |
| 100 | temp = temp->parent; |
| 101 | temp->color = PJ_RBCOLOR_RED; |
| 102 | right_rotate( tree, temp); |
| 103 | } |
| 104 | } else { |
| 105 | temp = parent->parent->left; |
| 106 | if (temp->color == PJ_RBCOLOR_RED) { |
| 107 | temp->color = PJ_RBCOLOR_BLACK; |
| 108 | node = parent; |
| 109 | node->color = PJ_RBCOLOR_BLACK; |
| 110 | node = node->parent; |
| 111 | node->color = PJ_RBCOLOR_RED; |
| 112 | } else { |
| 113 | if (node == parent->left) { |
| 114 | node = parent; |
| 115 | right_rotate(tree, node); |
| 116 | } |
| 117 | temp = node->parent; |
| 118 | temp->color = PJ_RBCOLOR_BLACK; |
| 119 | temp = temp->parent; |
| 120 | temp->color = PJ_RBCOLOR_RED; |
| 121 | left_rotate(tree, temp); |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | tree->root->color = PJ_RBCOLOR_BLACK; |
| 127 | } |
| 128 | |
| 129 | |
| 130 | static void delete_fixup( pj_rbtree *tree, pj_rbtree_node *node ) |
| 131 | { |
| 132 | pj_rbtree_node *temp; |
| 133 | |
| 134 | PJ_CHECK_STACK(); |
| 135 | |
| 136 | while (node != tree->root && node->color == PJ_RBCOLOR_BLACK) { |
| 137 | if (node->parent->left == node) { |
| 138 | temp = node->parent->right; |
| 139 | if (temp->color == PJ_RBCOLOR_RED) { |
| 140 | temp->color = PJ_RBCOLOR_BLACK; |
| 141 | node->parent->color = PJ_RBCOLOR_RED; |
| 142 | left_rotate(tree, node->parent); |
| 143 | temp = node->parent->right; |
| 144 | } |
| 145 | if (temp->left->color == PJ_RBCOLOR_BLACK && |
| 146 | temp->right->color == PJ_RBCOLOR_BLACK) |
| 147 | { |
| 148 | temp->color = PJ_RBCOLOR_RED; |
| 149 | node = node->parent; |
| 150 | } else { |
| 151 | if (temp->right->color == PJ_RBCOLOR_BLACK) { |
| 152 | temp->left->color = PJ_RBCOLOR_BLACK; |
| 153 | temp->color = PJ_RBCOLOR_RED; |
| 154 | right_rotate( tree, temp); |
| 155 | temp = node->parent->right; |
| 156 | } |
| 157 | temp->color = node->parent->color; |
| 158 | temp->right->color = PJ_RBCOLOR_BLACK; |
| 159 | node->parent->color = PJ_RBCOLOR_BLACK; |
| 160 | left_rotate(tree, node->parent); |
| 161 | node = tree->root; |
| 162 | } |
| 163 | } else { |
| 164 | temp = node->parent->left; |
| 165 | if (temp->color == PJ_RBCOLOR_RED) { |
| 166 | temp->color = PJ_RBCOLOR_BLACK; |
| 167 | node->parent->color = PJ_RBCOLOR_RED; |
| 168 | right_rotate( tree, node->parent); |
| 169 | temp = node->parent->left; |
| 170 | } |
| 171 | if (temp->right->color == PJ_RBCOLOR_BLACK && |
| 172 | temp->left->color == PJ_RBCOLOR_BLACK) |
| 173 | { |
| 174 | temp->color = PJ_RBCOLOR_RED; |
| 175 | node = node->parent; |
| 176 | } else { |
| 177 | if (temp->left->color == PJ_RBCOLOR_BLACK) { |
| 178 | temp->right->color = PJ_RBCOLOR_BLACK; |
| 179 | temp->color = PJ_RBCOLOR_RED; |
| 180 | left_rotate( tree, temp); |
| 181 | temp = node->parent->left; |
| 182 | } |
| 183 | temp->color = node->parent->color; |
| 184 | node->parent->color = PJ_RBCOLOR_BLACK; |
| 185 | temp->left->color = PJ_RBCOLOR_BLACK; |
| 186 | right_rotate(tree, node->parent); |
| 187 | node = tree->root; |
| 188 | } |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | node->color = PJ_RBCOLOR_BLACK; |
| 193 | } |
| 194 | |
| 195 | |
| 196 | PJ_DEF(void) pj_rbtree_init( pj_rbtree *tree, pj_rbtree_comp *comp ) |
| 197 | { |
| 198 | PJ_CHECK_STACK(); |
| 199 | |
| 200 | tree->null = tree->root = &tree->null_node; |
| 201 | tree->null->key = NULL; |
| 202 | tree->null->user_data = NULL; |
| 203 | tree->size = 0; |
| 204 | tree->null->left = tree->null->right = tree->null->parent = tree->null; |
| 205 | tree->null->color = PJ_RBCOLOR_BLACK; |
| 206 | tree->comp = comp; |
| 207 | } |
| 208 | |
| 209 | PJ_DEF(pj_rbtree_node*) pj_rbtree_first( pj_rbtree *tree ) |
| 210 | { |
| 211 | register pj_rbtree_node *node = tree->root; |
| 212 | register pj_rbtree_node *null = tree->null; |
| 213 | |
| 214 | PJ_CHECK_STACK(); |
| 215 | |
| 216 | while (node->left != null) |
| 217 | node = node->left; |
| 218 | return node != null ? node : NULL; |
| 219 | } |
| 220 | |
| 221 | PJ_DEF(pj_rbtree_node*) pj_rbtree_last( pj_rbtree *tree ) |
| 222 | { |
| 223 | register pj_rbtree_node *node = tree->root; |
| 224 | register pj_rbtree_node *null = tree->null; |
| 225 | |
| 226 | PJ_CHECK_STACK(); |
| 227 | |
| 228 | while (node->right != null) |
| 229 | node = node->right; |
| 230 | return node != null ? node : NULL; |
| 231 | } |
| 232 | |
| 233 | PJ_DEF(pj_rbtree_node*) pj_rbtree_next( pj_rbtree *tree, |
| 234 | register pj_rbtree_node *node ) |
| 235 | { |
| 236 | register pj_rbtree_node *null = tree->null; |
| 237 | |
| 238 | PJ_CHECK_STACK(); |
| 239 | |
| 240 | if (node->right != null) { |
| 241 | for (node=node->right; node->left!=null; node = node->left) |
| 242 | /* void */; |
| 243 | } else { |
| 244 | register pj_rbtree_node *temp = node->parent; |
| 245 | while (temp!=null && temp->right==node) { |
| 246 | node = temp; |
| 247 | temp = temp->parent; |
| 248 | } |
| 249 | node = temp; |
| 250 | } |
| 251 | return node != null ? node : NULL; |
| 252 | } |
| 253 | |
| 254 | PJ_DEF(pj_rbtree_node*) pj_rbtree_prev( pj_rbtree *tree, |
| 255 | register pj_rbtree_node *node ) |
| 256 | { |
| 257 | register pj_rbtree_node *null = tree->null; |
| 258 | |
| 259 | PJ_CHECK_STACK(); |
| 260 | |
| 261 | if (node->left != null) { |
| 262 | for (node=node->left; node->right!=null; node=node->right) |
| 263 | /* void */; |
| 264 | } else { |
| 265 | register pj_rbtree_node *temp = node->parent; |
| 266 | while (temp!=null && temp->left==node) { |
| 267 | node = temp; |
| 268 | temp = temp->parent; |
| 269 | } |
| 270 | node = temp; |
| 271 | } |
| 272 | return node != null ? node : NULL; |
| 273 | } |
| 274 | |
| 275 | PJ_DEF(int) pj_rbtree_insert( pj_rbtree *tree, |
| 276 | pj_rbtree_node *element ) |
| 277 | { |
| 278 | int rv = 0; |
| 279 | pj_rbtree_node *node, *parent = tree->null, |
| 280 | *null = tree->null; |
| 281 | pj_rbtree_comp *comp = tree->comp; |
| 282 | |
| 283 | PJ_CHECK_STACK(); |
| 284 | |
| 285 | node = tree->root; |
| 286 | while (node != null) { |
| 287 | rv = (*comp)(element->key, node->key); |
| 288 | if (rv == 0) { |
| 289 | /* found match, i.e. entry with equal key already exist */ |
| 290 | return -1; |
| 291 | } |
| 292 | parent = node; |
| 293 | node = rv < 0 ? node->left : node->right; |
| 294 | } |
| 295 | |
| 296 | element->color = PJ_RBCOLOR_RED; |
| 297 | element->left = element->right = null; |
| 298 | |
| 299 | node = element; |
| 300 | if (parent != null) { |
| 301 | node->parent = parent; |
| 302 | if (rv < 0) |
| 303 | parent->left = node; |
| 304 | else |
| 305 | parent->right = node; |
| 306 | insert_fixup( tree, node); |
| 307 | } else { |
| 308 | tree->root = node; |
| 309 | node->parent = null; |
| 310 | node->color = PJ_RBCOLOR_BLACK; |
| 311 | } |
| 312 | |
| 313 | ++tree->size; |
| 314 | return 0; |
| 315 | } |
| 316 | |
| 317 | |
| 318 | PJ_DEF(pj_rbtree_node*) pj_rbtree_find( pj_rbtree *tree, |
| 319 | const void *key ) |
| 320 | { |
| 321 | int rv; |
| 322 | pj_rbtree_node *node = tree->root; |
| 323 | pj_rbtree_node *null = tree->null; |
| 324 | pj_rbtree_comp *comp = tree->comp; |
| 325 | |
| 326 | while (node != null) { |
| 327 | rv = (*comp)(key, node->key); |
| 328 | if (rv == 0) |
| 329 | return node; |
| 330 | node = rv < 0 ? node->left : node->right; |
| 331 | } |
| 332 | return node != null ? node : NULL; |
| 333 | } |
| 334 | |
| 335 | PJ_DEF(pj_rbtree_node*) pj_rbtree_erase( pj_rbtree *tree, |
| 336 | pj_rbtree_node *node ) |
| 337 | { |
| 338 | pj_rbtree_node *succ; |
| 339 | pj_rbtree_node *null = tree->null; |
| 340 | pj_rbtree_node *child; |
| 341 | pj_rbtree_node *parent; |
| 342 | |
| 343 | PJ_CHECK_STACK(); |
| 344 | |
| 345 | if (node->left == null || node->right == null) { |
| 346 | succ = node; |
| 347 | } else { |
| 348 | for (succ=node->right; succ->left!=null; succ=succ->left) |
| 349 | /* void */; |
| 350 | } |
| 351 | |
| 352 | child = succ->left != null ? succ->left : succ->right; |
| 353 | parent = succ->parent; |
| 354 | child->parent = parent; |
| 355 | |
| 356 | if (parent != null) { |
| 357 | if (parent->left == succ) |
| 358 | parent->left = child; |
| 359 | else |
| 360 | parent->right = child; |
| 361 | } else |
| 362 | tree->root = child; |
| 363 | |
| 364 | if (succ != node) { |
| 365 | succ->parent = node->parent; |
| 366 | succ->left = node->left; |
| 367 | succ->right = node->right; |
| 368 | succ->color = node->color; |
| 369 | |
| 370 | parent = node->parent; |
| 371 | if (parent != null) { |
| 372 | if (parent->left==node) |
| 373 | parent->left=succ; |
| 374 | else |
| 375 | parent->right=succ; |
| 376 | } |
| 377 | if (node->left != null) |
| 378 | node->left->parent = succ;; |
| 379 | if (node->right != null) |
| 380 | node->right->parent = succ; |
| 381 | |
| 382 | if (tree->root == node) |
| 383 | tree->root = succ; |
| 384 | } |
| 385 | |
| 386 | if (succ->color == PJ_RBCOLOR_BLACK) { |
| 387 | if (child != null) |
| 388 | delete_fixup(tree, child); |
| 389 | tree->null->color = PJ_RBCOLOR_BLACK; |
| 390 | } |
| 391 | |
| 392 | --tree->size; |
| 393 | return node; |
| 394 | } |
| 395 | |
| 396 | |
| 397 | PJ_DEF(unsigned) pj_rbtree_max_height( pj_rbtree *tree, |
| 398 | pj_rbtree_node *node ) |
| 399 | { |
| 400 | unsigned l, r; |
| 401 | |
| 402 | PJ_CHECK_STACK(); |
| 403 | |
| 404 | if (node==NULL) |
| 405 | node = tree->root; |
| 406 | |
| 407 | l = node->left != tree->null ? pj_rbtree_max_height(tree,node->left)+1 : 0; |
| 408 | r = node->right != tree->null ? pj_rbtree_max_height(tree,node->right)+1 : 0; |
| 409 | return l > r ? l : r; |
| 410 | } |
| 411 | |
| 412 | PJ_DEF(unsigned) pj_rbtree_min_height( pj_rbtree *tree, |
| 413 | pj_rbtree_node *node ) |
| 414 | { |
| 415 | unsigned l, r; |
| 416 | |
| 417 | PJ_CHECK_STACK(); |
| 418 | |
| 419 | if (node==NULL) |
| 420 | node=tree->root; |
| 421 | |
| 422 | l = (node->left != tree->null) ? pj_rbtree_max_height(tree,node->left)+1 : 0; |
| 423 | r = (node->right != tree->null) ? pj_rbtree_max_height(tree,node->right)+1 : 0; |
| 424 | return l > r ? r : l; |
| 425 | } |
| 426 | |
| 427 | |