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| 35 | * @brief AVL tree implementation. |
35 | * @brief AVL tree implementation. |
| 36 | * |
36 | * |
| 37 | * This file implements AVL tree type and operations. |
37 | * This file implements AVL tree type and operations. |
| 38 | * |
38 | * |
| 39 | * Implemented AVL tree has the following properties: |
39 | * Implemented AVL tree has the following properties: |
| 40 | * @li It is binary search tree with non-unique keys. |
40 | * @li It is a binary search tree with non-unique keys. |
| 41 | * @li Difference of heights of left and right subtree of every node is max 1. |
41 | * @li Difference of heights of the left and the right subtree of every node is |
| - | 42 | * one at maximum. |
|
| 42 | * |
43 | * |
| 43 | * Every node has pointer to its parent which allows insertion of multiple identical keys |
44 | * Every node has a pointer to its parent which allows insertion of multiple |
| 44 | * into tree. |
45 | * identical keys into the tree. |
| 45 | * |
46 | * |
| 46 | * Be careful of using this tree because of base atribute, which is added to every inserted |
47 | * Be careful when using this tree because of the base atribute which is added |
| 47 | * node key. There is no rule in which order nodes with the same key are visited. |
48 | * to every inserted node key. There is no rule in which order nodes with the |
| - | 49 | * same key are visited. |
|
| 48 | */ |
50 | */ |
| 49 | 51 | ||
| 50 | #include <adt/avl.h> |
52 | #include <adt/avl.h> |
| 51 | #include <debug.h> |
53 | #include <debug.h> |
| 52 | 54 | ||
| 53 | 55 | ||
| 54 | #define AVLTREE_LEFT 0 |
56 | #define LEFT 0 |
| 55 | #define AVLTREE_RIGHT 1 |
57 | #define RIGHT 1 |
| 56 | 58 | ||
| 57 | 59 | ||
| 58 | /** Search first occurence of given key in AVL tree. |
60 | /** Search for the first occurence of the given key in an AVL tree. |
| 59 | * |
61 | * |
| 60 | * @param t AVL tree. |
62 | * @param t AVL tree. |
| 61 | * @param key Key to be searched. |
63 | * @param key Key to be searched. |
| 62 | * |
64 | * |
| 63 | * @return Pointer to node or NULL if there is no such key. |
65 | * @return Pointer to a node or NULL if there is no such key. |
| 64 | */ |
66 | */ |
| 65 | avltree_node_t *avltree_search(avltree_t *t, uint64_t key) |
67 | avltree_node_t *avltree_search(avltree_t *t, uint64_t key) |
| 66 | { |
68 | { |
| 67 | avltree_node_t *p; |
69 | avltree_node_t *p; |
| 68 | 70 | ||
| Line 73... | Line 75... | ||
| 73 | while (p != NULL) { |
75 | while (p != NULL) { |
| 74 | if (p->key > key) |
76 | if (p->key > key) |
| 75 | p = p->lft; |
77 | p = p->lft; |
| 76 | else if (p->key < key) |
78 | else if (p->key < key) |
| 77 | p = p->rgt; |
79 | p = p->rgt; |
| 78 | else { |
80 | else |
| 79 | return p; |
81 | return p; |
| 80 | } |
- | |
| 81 | } |
82 | } |
| 82 | return NULL; |
83 | return NULL; |
| 83 | } |
84 | } |
| 84 | 85 | ||
| 85 | 86 | ||
| 86 | /** Find node with smallest key in AVL tree. |
87 | /** Find the node with the smallest key in an AVL tree. |
| 87 | * |
88 | * |
| 88 | * @param t AVL tree. |
89 | * @param t AVL tree. |
| 89 | * |
90 | * |
| 90 | * @return Pointer to node or NULL if there is no node in the tree. |
91 | * @return Pointer to a node or NULL if there is no node in the tree. |
| 91 | */ |
92 | */ |
| 92 | avltree_node_t *avltree_find_min(avltree_t *t) |
93 | avltree_node_t *avltree_find_min(avltree_t *t) |
| 93 | { |
94 | { |
| 94 | avltree_node_t *p = t->root; |
95 | avltree_node_t *p = t->root; |
| 95 | 96 | ||
| 96 | /* |
97 | /* |
| 97 | * Check whether tree is empty. |
98 | * Check whether the tree is empty. |
| 98 | */ |
99 | */ |
| - | 100 | if (!p) |
|
| 99 | if (!p) return NULL; |
101 | return NULL; |
| 100 | 102 | ||
| 101 | /* |
103 | /* |
| 102 | * Iteratively descend to the leftmost leaf in the tree. |
104 | * Iteratively descend to the leftmost leaf in the tree. |
| 103 | */ |
105 | */ |
| 104 | while (p->lft != NULL) |
106 | while (p->lft != NULL) |
| Line 126... | Line 128... | ||
| 126 | /* |
128 | /* |
| 127 | * Creating absolute key. |
129 | * Creating absolute key. |
| 128 | */ |
130 | */ |
| 129 | key = newnode->key + t->base; |
131 | key = newnode->key + t->base; |
| 130 | 132 | ||
| 131 | - | ||
| 132 | /* |
133 | /* |
| 133 | * Iteratively descend to the leaf that can contain new node. |
134 | * Iteratively descend to the leaf that can contain the new node. |
| 134 | * Last node with non-zero balance in the way to leaf is stored as top - |
135 | * Last node with non-zero balance in the way to leaf is stored as top - |
| 135 | * it si place of possible balance fault. |
136 | * it is a place of possible inbalance. |
| 136 | */ |
137 | */ |
| 137 | dpc = &t->root; |
138 | dpc = &t->root; |
| 138 | gpa = NULL; |
139 | gpa = NULL; |
| 139 | top = t->root; |
140 | top = t->root; |
| 140 | while ((par = (*dpc)) != NULL) { |
141 | while ((par = (*dpc)) != NULL) { |
| 141 | if (par->balance != 0) { |
142 | if (par->balance != 0) { |
| 142 | top = par; |
143 | top = par; |
| 143 | } |
144 | } |
| 144 | gpa = par; |
145 | gpa = par; |
| 145 | dpc = par->key > key? &par->lft: &par->rgt; |
146 | dpc = par->key > key ? &par->lft: &par->rgt; |
| 146 | } |
147 | } |
| 147 | 148 | ||
| 148 | /* |
149 | /* |
| 149 | * Initialize new node. |
150 | * Initialize new node. |
| 150 | */ |
151 | */ |
| Line 153... | Line 154... | ||
| 153 | newnode->rgt = NULL; |
154 | newnode->rgt = NULL; |
| 154 | newnode->par = gpa; |
155 | newnode->par = gpa; |
| 155 | newnode->balance = 0; |
156 | newnode->balance = 0; |
| 156 | 157 | ||
| 157 | /* |
158 | /* |
| 158 | * Insert first node into empty tree. |
159 | * Insert first node into the empty tree. |
| 159 | */ |
160 | */ |
| 160 | if (t->root == NULL) { |
161 | if (t->root == NULL) { |
| 161 | *dpc = newnode; |
162 | *dpc = newnode; |
| 162 | return; |
163 | return; |
| 163 | } |
164 | } |
| Line 166... | Line 167... | ||
| 166 | * Insert new node into previously found leaf place. |
167 | * Insert new node into previously found leaf place. |
| 167 | */ |
168 | */ |
| 168 | *dpc = newnode; |
169 | *dpc = newnode; |
| 169 | 170 | ||
| 170 | /* |
171 | /* |
| 171 | * If tree contains one node - end. |
172 | * If the tree contains one node - end. |
| 172 | */ |
173 | */ |
| 173 | if (top == NULL) return; |
174 | if (top == NULL) |
| - | 175 | return; |
|
| 174 | 176 | ||
| 175 | /* |
177 | /* |
| 176 | * Store pointer of top's father which points to the node with potentialy broken |
178 | * Store pointer of top's father which points to the node with |
| 177 | * balance (top). |
179 | * potentially broken balance (top). |
| 178 | */ |
180 | */ |
| 179 | if (top->par == NULL) |
181 | if (top->par == NULL) { |
| 180 | dpc = &t->root; |
182 | dpc = &t->root; |
| 181 | else |
183 | } else { |
| 182 | if (top->par->lft == top) |
184 | if (top->par->lft == top) |
| 183 | dpc = &(top->par->lft); |
185 | dpc = &top->par->lft; |
| 184 | else |
186 | else |
| 185 | dpc = &(top->par->rgt); |
187 | dpc = &top->par->rgt; |
| - | 188 | } |
|
| 186 | 189 | ||
| 187 | /* |
190 | /* |
| 188 | * Repair all balances on the way from top node to newly inserted node. |
191 | * Repair all balances on the way from top node to the newly inserted |
| - | 192 | * node. |
|
| 189 | */ |
193 | */ |
| 190 | par = top; |
194 | par = top; |
| 191 | while (par != newnode) { |
195 | while (par != newnode) { |
| 192 | if (par->key > key) { |
196 | if (par->key > key) { |
| 193 | par->balance--; |
197 | par->balance--; |
| Line 197... | Line 201... | ||
| 197 | par = par->rgt; |
201 | par = par->rgt; |
| 198 | } |
202 | } |
| 199 | } |
203 | } |
| 200 | 204 | ||
| 201 | /* |
205 | /* |
| 202 | * To balance tree we must check and balance top node. |
206 | * To balance the tree, we must check and balance top node. |
| 203 | */ |
207 | */ |
| 204 | if (top->balance == -2) { |
208 | if (top->balance == -2) { |
| 205 | par = top->lft; |
209 | par = top->lft; |
| 206 | if (par->balance == -1) { |
210 | if (par->balance == -1) { |
| 207 | /* |
211 | /* |
| 208 | * LL rotation. |
212 | * LL rotation. |
| 209 | */ |
213 | */ |
| 210 | top->lft = par->rgt; |
214 | top->lft = par->rgt; |
| 211 | if (top->lft != NULL) top->lft->par = top; |
215 | if (top->lft != NULL) |
| - | 216 | top->lft->par = top; |
|
| 212 | par->par = top->par; |
217 | par->par = top->par; |
| 213 | top->par = par; |
218 | top->par = par; |
| 214 | par->rgt = top; |
219 | par->rgt = top; |
| 215 | par->balance = top->balance = 0; |
220 | par->balance = top->balance = 0; |
| 216 | *dpc = par; |
221 | *dpc = par; |
| Line 220... | Line 225... | ||
| 220 | */ |
225 | */ |
| 221 | ASSERT(par->balance == 1); |
226 | ASSERT(par->balance == 1); |
| 222 | 227 | ||
| 223 | gpa = par->rgt; |
228 | gpa = par->rgt; |
| 224 | par->rgt = gpa->lft; |
229 | par->rgt = gpa->lft; |
| 225 | if (gpa->lft != NULL) gpa->lft->par = par; |
230 | if (gpa->lft != NULL) |
| - | 231 | gpa->lft->par = par; |
|
| 226 | gpa->lft = par; |
232 | gpa->lft = par; |
| 227 | par->par = gpa; |
233 | par->par = gpa; |
| 228 | top->lft = gpa->rgt; |
234 | top->lft = gpa->rgt; |
| 229 | if (gpa->rgt != NULL) gpa->rgt->par = top; |
235 | if (gpa->rgt != NULL) |
| - | 236 | gpa->rgt->par = top; |
|
| 230 | gpa->rgt = top; |
237 | gpa->rgt = top; |
| 231 | gpa->par = top->par; |
238 | gpa->par = top->par; |
| 232 | top->par = gpa; |
239 | top->par = gpa; |
| 233 | 240 | ||
| 234 | if (gpa->balance == -1) { |
241 | if (gpa->balance == -1) { |
| Line 248... | Line 255... | ||
| 248 | if (par->balance == 1) { |
255 | if (par->balance == 1) { |
| 249 | /* |
256 | /* |
| 250 | * RR rotation. |
257 | * RR rotation. |
| 251 | */ |
258 | */ |
| 252 | top->rgt = par->lft; |
259 | top->rgt = par->lft; |
| 253 | if (top->rgt != NULL) top->rgt->par = top; |
260 | if (top->rgt != NULL) |
| - | 261 | top->rgt->par = top; |
|
| 254 | par->par = top->par; |
262 | par->par = top->par; |
| 255 | top->par = par; |
263 | top->par = par; |
| 256 | par->lft = top; |
264 | par->lft = top; |
| 257 | par->balance = top->balance = 0; |
265 | par->balance = top->balance = 0; |
| 258 | *dpc = par; |
266 | *dpc = par; |
| Line 262... | Line 270... | ||
| 262 | */ |
270 | */ |
| 263 | ASSERT(par->balance == -1); |
271 | ASSERT(par->balance == -1); |
| 264 | 272 | ||
| 265 | gpa = par->lft; |
273 | gpa = par->lft; |
| 266 | par->lft = gpa->rgt; |
274 | par->lft = gpa->rgt; |
| 267 | if (gpa->rgt != NULL) gpa->rgt->par = par; |
275 | if (gpa->rgt != NULL) |
| - | 276 | gpa->rgt->par = par; |
|
| 268 | gpa->rgt = par; |
277 | gpa->rgt = par; |
| 269 | par->par = gpa; |
278 | par->par = gpa; |
| 270 | top->rgt = gpa->lft; |
279 | top->rgt = gpa->lft; |
| 271 | if (gpa->lft != NULL) gpa->lft->par = top; |
280 | if (gpa->lft != NULL) |
| - | 281 | gpa->lft->par = top; |
|
| 272 | gpa->lft = top; |
282 | gpa->lft = top; |
| 273 | gpa->par = top->par; |
283 | gpa->par = top->par; |
| 274 | top->par = gpa; |
284 | top->par = gpa; |
| 275 | 285 | ||
| 276 | if (gpa->balance == 1) { |
286 | if (gpa->balance == 1) { |
| Line 292... | Line 302... | ||
| 292 | return; |
302 | return; |
| 293 | } |
303 | } |
| 294 | 304 | ||
| 295 | } |
305 | } |
| 296 | 306 | ||
| 297 | /** Delete node from AVL tree. |
307 | /** Delete a node from the AVL tree. |
| 298 | * |
308 | * |
| 299 | * Because of allowed multiple identical keys parent pointers are essential |
309 | * Because multiple identical keys are allowed, the parent pointers are |
| 300 | * during deletition. |
310 | * essential during deletion. |
| 301 | * |
311 | * |
| 302 | * @param t AVL tree structure. |
312 | * @param t AVL tree structure. |
| 303 | * @param node Address of node which will be deleted. |
313 | * @param node Address of the node which will be deleted. |
| 304 | */ |
314 | */ |
| 305 | void avltree_delete(avltree_t *t, avltree_node_t *node) |
315 | void avltree_delete(avltree_t *t, avltree_node_t *node) |
| 306 | { |
316 | { |
| 307 | avltree_node_t *cur; |
317 | avltree_node_t *cur; |
| 308 | avltree_node_t *par; |
318 | avltree_node_t *par; |
| Line 310... | Line 320... | ||
| 310 | uint8_t dir; |
320 | uint8_t dir; |
| 311 | 321 | ||
| 312 | ASSERT(t); |
322 | ASSERT(t); |
| 313 | ASSERT(node); |
323 | ASSERT(node); |
| 314 | 324 | ||
| 315 | - | ||
| 316 | if (node->lft == NULL) { |
325 | if (node->lft == NULL) { |
| 317 | if (node->rgt) { |
326 | if (node->rgt) { |
| 318 | /* |
327 | /* |
| 319 | * Replace node with its only right son. |
328 | * Replace the node with its only right son. |
| 320 | * |
329 | * |
| 321 | * Balance of right son will be repaired in balancing cycle. |
330 | * Balance of the right son will be repaired in the |
| - | 331 | * balancing cycle. |
|
| 322 | */ |
332 | */ |
| 323 | cur = node->rgt; |
333 | cur = node->rgt; |
| 324 | cur->par = node->par; |
334 | cur->par = node->par; |
| 325 | gpa = cur; |
335 | gpa = cur; |
| 326 | dir = AVLTREE_RIGHT; |
336 | dir = RIGHT; |
| 327 | cur->balance = node->balance; |
337 | cur->balance = node->balance; |
| 328 | } else { |
338 | } else { |
| 329 | if (node->par == NULL) { |
339 | if (node->par == NULL) { |
| 330 | /* |
340 | /* |
| 331 | * Tree has only one node - it will be empty tree and balancing can end. |
341 | * The tree has only one node - it will become |
| - | 342 | * an empty tree and the balancing can end. |
|
| 332 | */ |
343 | */ |
| 333 | t->root = NULL; |
344 | t->root = NULL; |
| 334 | return; |
345 | return; |
| 335 | } |
346 | } |
| 336 | /* |
347 | /* |
| 337 | * Node has no child, will be deleted with no substitution. |
348 | * The node has no child, it will be deleted with no |
| - | 349 | * substitution. |
|
| 338 | */ |
350 | */ |
| 339 | gpa = node->par; |
351 | gpa = node->par; |
| 340 | cur = NULL; |
352 | cur = NULL; |
| 341 | dir = (gpa->lft == node)? AVLTREE_LEFT: AVLTREE_RIGHT; |
353 | dir = (gpa->lft == node) ? LEFT: RIGHT; |
| 342 | } |
354 | } |
| 343 | } else { |
355 | } else { |
| 344 | /* |
356 | /* |
| 345 | * Node has left and right son. Find a node with smallest key in left subtree |
357 | * The node has left and right son. Find a node with the |
| - | 358 | * smallest key in the left subtree and replace the deleted node |
|
| 346 | * and replace deleted node with that node. |
359 | * with that node. |
| 347 | */ |
360 | */ |
| 348 | for (cur = node->lft; cur->rgt != NULL; cur = cur->rgt) |
361 | for (cur = node->lft; cur->rgt != NULL; cur = cur->rgt) |
| 349 | ; |
362 | ; |
| 350 | - | ||
| 351 | //cur obsahuje uzel, ktery vlozim misto uzlu node |
- | |
| 352 | 363 | ||
| 353 | if (cur != node->lft) { |
364 | if (cur != node->lft) { |
| 354 | /* |
365 | /* |
| 355 | * The most right node of deleted node's left subtree was found. Replace |
366 | * The rightmost node of the deleted node's left subtree |
| - | 367 | * was found. Replace the deleted node with this node. |
|
| 356 | * deleted node with this node. Cutting founded node has two cases in |
368 | * Cutting off of the found node has two cases that |
| 357 | * dependence on its left son. |
369 | * depend on its left son. |
| 358 | */ |
370 | */ |
| 359 | if (cur->lft) { |
371 | if (cur->lft) { |
| 360 | /* |
372 | /* |
| 361 | * Founded node has left son. |
373 | * The found node has a left son. |
| 362 | */ |
374 | */ |
| 363 | gpa = cur->lft; |
375 | gpa = cur->lft; |
| 364 | gpa->par = cur->par; |
376 | gpa->par = cur->par; |
| 365 | dir = AVLTREE_LEFT; |
377 | dir = LEFT; |
| 366 | gpa->balance = cur->balance; |
378 | gpa->balance = cur->balance; |
| 367 | } else { |
379 | } else { |
| 368 | dir = AVLTREE_RIGHT; |
380 | dir = RIGHT; |
| 369 | gpa = cur->par; |
381 | gpa = cur->par; |
| 370 | } |
382 | } |
| 371 | cur->par->rgt = cur->lft; |
383 | cur->par->rgt = cur->lft; |
| 372 | cur->lft = node->lft; |
384 | cur->lft = node->lft; |
| 373 | cur->lft->par = cur; |
385 | cur->lft->par = cur; |
| 374 | } else { |
386 | } else { |
| 375 | /* |
387 | /* |
| - | 388 | * The left son of the node hasn't got a right son. The |
|
| 376 | * Left son of node hasn't got right son. Left son will take deleted node's place. |
389 | * left son will take the deleted node's place. |
| 377 | */ |
390 | */ |
| 378 | dir = AVLTREE_LEFT; |
391 | dir = LEFT; |
| 379 | gpa = cur; |
392 | gpa = cur; |
| 380 | } |
393 | } |
| - | 394 | if (node->rgt) |
|
| 381 | if (node->rgt) node->rgt->par = cur; |
395 | node->rgt->par = cur; |
| 382 | cur->rgt = node->rgt; |
396 | cur->rgt = node->rgt; |
| 383 | cur->balance = node->balance; |
397 | cur->balance = node->balance; |
| 384 | cur->par = node->par; |
398 | cur->par = node->par; |
| 385 | } |
399 | } |
| 386 | 400 | ||
| 387 | /* |
401 | /* |
| 388 | * Repair parent nodes pointer which pointed previously to deleted node. |
402 | * Repair the parent node's pointer which pointed previously to the |
| - | 403 | * deleted node. |
|
| 389 | */ |
404 | */ |
| 390 | if (node->par == NULL) { |
405 | if (node->par == NULL) { |
| 391 | t->root = cur; |
406 | t->root = cur; |
| 392 | } else { |
407 | } else { |
| 393 | if (node->par->lft == node) { |
408 | if (node->par->lft == node) { |
| Line 396... | Line 411... | ||
| 396 | node->par->rgt = cur; |
411 | node->par->rgt = cur; |
| 397 | } |
412 | } |
| 398 | } |
413 | } |
| 399 | 414 | ||
| 400 | /* |
415 | /* |
| 401 | * Repair cycle which repairs balances of nodes in way from cutted noded down to root. |
416 | * Repair cycle which repairs balances of nodes on the way from from the |
| - | 417 | * cut-off node up to the root. |
|
| 402 | */ |
418 | */ |
| 403 | for(;;) { |
419 | for (;;) { |
| 404 | if (dir == AVLTREE_LEFT) { |
420 | if (dir == LEFT) { |
| 405 | /* |
421 | /* |
| 406 | * Deletition was made in left subtree. |
422 | * Deletion was made in the left subtree. |
| 407 | */ |
423 | */ |
| 408 | gpa->balance++; |
424 | gpa->balance++; |
| 409 | if (gpa->balance == +1) { |
425 | if (gpa->balance == 1) { |
| 410 | /* |
426 | /* |
| 411 | * Stop balancing, tree is balanced. |
427 | * Stop balancing, the tree is balanced. |
| 412 | */ |
428 | */ |
| 413 | break; |
429 | break; |
| 414 | } else if (gpa->balance == +2) { |
430 | } else if (gpa->balance == 2) { |
| 415 | /* |
431 | /* |
| 416 | * Bad balance, heights of left and right subtrees differs more then is allowed. |
432 | * Bad balance, heights of left and right |
| - | 433 | * subtrees differ more than by one. |
|
| 417 | */ |
434 | */ |
| 418 | par = gpa->rgt; |
435 | par = gpa->rgt; |
| 419 | 436 | ||
| 420 | if (par->balance == -1) { |
437 | if (par->balance == -1) { |
| 421 | /* |
438 | /* |
| Line 427... | Line 444... | ||
| 427 | cur->rgt = par; |
444 | cur->rgt = par; |
| 428 | gpa->rgt = cur->lft; |
445 | gpa->rgt = cur->lft; |
| 429 | cur->lft = gpa; |
446 | cur->lft = gpa; |
| 430 | 447 | ||
| 431 | /* |
448 | /* |
| 432 | * Repair balances and paternity of childs in dependence on |
449 | * Repair balances and paternity of |
| - | 450 | * children, depending on the balance |
|
| 433 | * balance factor of grand child (cur). |
451 | * factor of the grand child (cur). |
| 434 | */ |
452 | */ |
| 435 | if (cur->balance == +1) { |
453 | if (cur->balance == 1) { |
| 436 | par->balance = 0; |
454 | par->balance = 0; |
| 437 | gpa->balance = -1; |
455 | gpa->balance = -1; |
| - | 456 | if (gpa->rgt) |
|
| 438 | if (gpa->rgt) gpa->rgt->par = gpa; |
457 | gpa->rgt->par = gpa; |
| 439 | par->lft->par = par; |
458 | par->lft->par = par; |
| 440 | } else if (cur->balance == 0) { |
459 | } else if (cur->balance == 0) { |
| 441 | par->balance = gpa->balance = 0; |
460 | par->balance = gpa->balance = 0; |
| - | 461 | if (gpa->rgt) |
|
| 442 | if (gpa->rgt) gpa->rgt->par = gpa; |
462 | gpa->rgt->par = gpa; |
| - | 463 | if (par->lft) |
|
| 443 | if (par->lft) par->lft->par = par; |
464 | par->lft->par = par; |
| 444 | } else { |
465 | } else { |
| 445 | par->balance = +1; |
466 | par->balance = 1; |
| 446 | gpa->balance = 0; |
467 | gpa->balance = 0; |
| - | 468 | if (par->lft) |
|
| 447 | if (par->lft) par->lft->par = par; |
469 | par->lft->par = par; |
| 448 | gpa->rgt->par = gpa; |
470 | gpa->rgt->par = gpa; |
| 449 | } |
471 | } |
| 450 | cur->balance = 0; |
472 | cur->balance = 0; |
| 451 | 473 | ||
| 452 | /* |
474 | /* |
| Line 455... | Line 477... | ||
| 455 | cur->par = gpa->par; |
477 | cur->par = gpa->par; |
| 456 | gpa->par = cur; |
478 | gpa->par = cur; |
| 457 | par->par = cur; |
479 | par->par = cur; |
| 458 | 480 | ||
| 459 | /* |
481 | /* |
| - | 482 | * Repair the pointer which pointed to |
|
| 460 | * Repair pointer which pointed to balanced node. If it was root then balancing |
483 | * the balanced node. If it was root |
| - | 484 | * then the balancing is finished. |
|
| - | 485 | * Otherwise continue with the next |
|
| 461 | * is finished else continue in next iteration (parent node). |
486 | * iteration (parent node). |
| 462 | */ |
487 | */ |
| 463 | if (cur->par == NULL) { |
488 | if (cur->par == NULL) { |
| 464 | t->root = cur; |
489 | t->root = cur; |
| 465 | break; |
490 | break; |
| 466 | } else |
491 | } else { |
| 467 | if (cur->par->lft == gpa) { |
492 | if (cur->par->lft == gpa) { |
| 468 | cur->par->lft = cur; |
493 | cur->par->lft = cur; |
| 469 | dir = AVLTREE_LEFT; |
494 | dir = LEFT; |
| 470 | } else { |
495 | } else { |
| 471 | cur->par->rgt = cur; |
496 | cur->par->rgt = cur; |
| 472 | dir = AVLTREE_RIGHT; |
497 | dir = RIGHT; |
| 473 | } |
498 | } |
| - | 499 | } |
|
| 474 | gpa = cur->par; |
500 | gpa = cur->par; |
| 475 | } else { |
501 | } else { |
| 476 | /* |
502 | /* |
| 477 | * RR rotation. |
503 | * RR rotation. |
| 478 | */ |
504 | */ |
| 479 | 505 | ||
| 480 | gpa->rgt = par->lft; |
506 | gpa->rgt = par->lft; |
| - | 507 | if (par->lft) |
|
| 481 | if (par->lft) par->lft->par = gpa; |
508 | par->lft->par = gpa; |
| 482 | par->lft = gpa; |
509 | par->lft = gpa; |
| 483 | 510 | ||
| 484 | /* |
511 | /* |
| 485 | * Repair paternity. |
512 | * Repair paternity. |
| 486 | */ |
513 | */ |
| 487 | par->par = gpa->par; |
514 | par->par = gpa->par; |
| 488 | gpa->par = par; |
515 | gpa->par = par; |
| 489 | 516 | ||
| 490 | if (par->balance == 0) { |
517 | if (par->balance == 0) { |
| 491 | /* |
518 | /* |
| - | 519 | * The right child of the |
|
| - | 520 | * balanced node is balanced, |
|
| 492 | * Right child of balanced node is balanced, after RR rotation is done, whole |
521 | * after RR rotation is done, |
| 493 | * tree will be balanced. |
522 | * the whole tree will be |
| - | 523 | * balanced. |
|
| 494 | */ |
524 | */ |
| 495 | par->balance = -1; |
525 | par->balance = -1; |
| 496 | gpa->balance = +1; |
526 | gpa->balance = 1; |
| 497 | 527 | ||
| 498 | /* |
528 | /* |
| - | 529 | * Repair the pointer which |
|
| 499 | * Repair pointer which pointed to balanced node and finish balancing. |
530 | * pointed to the balanced node |
| - | 531 | * and finish balancing. |
|
| 500 | */ |
532 | */ |
| 501 | if (par->par == NULL) { |
533 | if (par->par == NULL) { |
| 502 | t->root = par; |
534 | t->root = par; |
| 503 | } else |
535 | } else { |
| 504 | if (par->par->lft == gpa) { |
536 | if (par->par->lft == |
| - | 537 | gpa) { |
|
| 505 | par->par->lft = par; |
538 | par->par->lft = |
| - | 539 | par; |
|
| 506 | } else { |
540 | } else { |
| 507 | par->par->rgt = par; |
541 | par->par->rgt = |
| - | 542 | par; |
|
| 508 | } |
543 | } |
| - | 544 | } |
|
| 509 | break; |
545 | break; |
| 510 | } else { |
546 | } else { |
| 511 | par->balance = gpa->balance = 0; |
547 | par->balance = gpa->balance = 0; |
| 512 | /* |
548 | /* |
| - | 549 | * Repair the pointer which |
|
| - | 550 | * pointed to the balanced node. |
|
| 513 | * Repair pointer which pointed to balanced node. If it was root then balancing |
551 | * If it was root then balancing |
| - | 552 | * is finished. Otherwise |
|
| - | 553 | * continue with the next |
|
| 514 | * is finished else continue in next iteration (parent node). |
554 | * iteration (parent node). |
| 515 | */ |
555 | */ |
| 516 | if (par->par == NULL) { |
556 | if (par->par == NULL) { |
| 517 | t->root = par; |
557 | t->root = par; |
| 518 | break; |
558 | break; |
| 519 | } else { |
559 | } else { |
| - | 560 | if (par->par->lft == |
|
| 520 | 561 | gpa) { |
|
| 521 | if (par->par->lft == gpa) { |
562 | par->par->lft = |
| 522 | par->par->lft = par; |
563 | par; |
| 523 | dir = AVLTREE_LEFT; |
564 | dir = LEFT; |
| 524 | } else { |
565 | } else { |
| 525 | par->par->rgt = par; |
566 | par->par->rgt = |
| - | 567 | par; |
|
| 526 | dir = AVLTREE_RIGHT; |
568 | dir = RIGHT; |
| 527 | } |
569 | } |
| 528 | } |
570 | } |
| 529 | } |
571 | } |
| 530 | gpa = par->par; |
572 | gpa = par->par; |
| 531 | } |
573 | } |
| 532 | } else { |
574 | } else { |
| 533 | /* |
575 | /* |
| - | 576 | * Repair the pointer which pointed to the |
|
| 534 | * Repair pointer which pointed to balanced node. If it was root then balancing |
577 | * balanced node. If it was root then balancing |
| 535 | * is finished else continue in next iteration (parent node). |
578 | * is finished else continue with the next |
| - | 579 | * iteration (parent node). |
|
| 536 | */ |
580 | */ |
| 537 | if (!gpa->par) break; |
581 | if (!gpa->par) |
| - | 582 | break; |
|
| 538 | 583 | ||
| 539 | if (gpa->par->lft == gpa) { |
584 | if (gpa->par->lft == gpa) { |
| 540 | dir = AVLTREE_LEFT; |
585 | dir = LEFT; |
| 541 | } else { |
586 | } else { |
| 542 | dir = AVLTREE_RIGHT; |
587 | dir = RIGHT; |
| 543 | } |
588 | } |
| 544 | gpa = gpa->par; |
589 | gpa = gpa->par; |
| 545 | } |
590 | } |
| 546 | } else { |
591 | } else { |
| 547 | /* |
592 | /* |
| 548 | * Deletition was made in right subtree. |
593 | * Deletion was made in the right subtree. |
| 549 | */ |
594 | */ |
| 550 | gpa->balance--; |
595 | gpa->balance--; |
| 551 | if (gpa->balance == -1) { |
596 | if (gpa->balance == -1) { |
| 552 | /* |
597 | /* |
| 553 | * Stop balancing, tree is balanced. |
598 | * Stop balancing, the tree is balanced. |
| 554 | */ |
599 | */ |
| 555 | break; |
600 | break; |
| 556 | } else if (gpa->balance == -2) { |
601 | } else if (gpa->balance == -2) { |
| 557 | /* |
602 | /* |
| 558 | * Bad balance, heights of left and right subtrees differs more then is allowed. |
603 | * Bad balance, heights of left and right |
| - | 604 | * subtrees differ more than by one. |
|
| 559 | */ |
605 | */ |
| 560 | par = gpa->lft; |
606 | par = gpa->lft; |
| 561 | 607 | ||
| 562 | if (par->balance == +1) { |
608 | if (par->balance == 1) { |
| 563 | /* |
609 | /* |
| 564 | * LR rotation. |
610 | * LR rotation. |
| 565 | */ |
611 | */ |
| 566 | 612 | ||
| 567 | cur = par->rgt; |
613 | cur = par->rgt; |
| Line 569... | Line 615... | ||
| 569 | cur->lft = par; |
615 | cur->lft = par; |
| 570 | gpa->lft = cur->rgt; |
616 | gpa->lft = cur->rgt; |
| 571 | cur->rgt = gpa; |
617 | cur->rgt = gpa; |
| 572 | 618 | ||
| 573 | /* |
619 | /* |
| 574 | * Repair balances and paternity of childs in dependence on |
620 | * Repair balances and paternity of |
| - | 621 | * children, depending on the balance |
|
| 575 | * balance factor of grand child (cur). |
622 | * factor of the grand child (cur). |
| 576 | */ |
623 | */ |
| 577 | if (cur->balance == -1) { |
624 | if (cur->balance == -1) { |
| 578 | par->balance = 0; |
625 | par->balance = 0; |
| 579 | gpa->balance = +1; |
626 | gpa->balance = 1; |
| - | 627 | if (gpa->lft) |
|
| 580 | if (gpa->lft) gpa->lft->par = gpa; |
628 | gpa->lft->par = gpa; |
| 581 | par->rgt->par = par; |
629 | par->rgt->par = par; |
| 582 | } else if (cur->balance == 0) { |
630 | } else if (cur->balance == 0) { |
| 583 | par->balance = gpa->balance = 0; |
631 | par->balance = gpa->balance = 0; |
| - | 632 | if (gpa->lft) |
|
| 584 | if (gpa->lft) gpa->lft->par = gpa; |
633 | gpa->lft->par = gpa; |
| - | 634 | if (par->rgt) |
|
| 585 | if (par->rgt) par->rgt->par = par; |
635 | par->rgt->par = par; |
| 586 | } else { |
636 | } else { |
| 587 | par->balance = -1; |
637 | par->balance = -1; |
| 588 | gpa->balance = 0; |
638 | gpa->balance = 0; |
| - | 639 | if (par->rgt) |
|
| 589 | if (par->rgt) par->rgt->par = par; |
640 | par->rgt->par = par; |
| 590 | gpa->lft->par = gpa; |
641 | gpa->lft->par = gpa; |
| 591 | } |
642 | } |
| 592 | cur->balance = 0; |
643 | cur->balance = 0; |
| 593 | 644 | ||
| 594 | /* |
645 | /* |
| Line 597... | Line 648... | ||
| 597 | cur->par = gpa->par; |
648 | cur->par = gpa->par; |
| 598 | gpa->par = cur; |
649 | gpa->par = cur; |
| 599 | par->par = cur; |
650 | par->par = cur; |
| 600 | 651 | ||
| 601 | /* |
652 | /* |
| - | 653 | * Repair the pointer which pointed to |
|
| 602 | * Repair pointer which pointed to balanced node. If it was root then balancing |
654 | * the balanced node. If it was root |
| - | 655 | * then balancing is finished. Otherwise |
|
| 603 | * is finished else continue in next iteration (parent node). |
656 | * continue with the next iteration |
| - | 657 | * (parent node). |
|
| 604 | */ |
658 | */ |
| 605 | if (cur->par == NULL) { |
659 | if (cur->par == NULL) { |
| 606 | t->root = cur; |
660 | t->root = cur; |
| 607 | break; |
661 | break; |
| 608 | } else |
662 | } else { |
| 609 | if (cur->par->lft == gpa) { |
663 | if (cur->par->lft == gpa) { |
| 610 | cur->par->lft = cur; |
664 | cur->par->lft = cur; |
| 611 | dir = AVLTREE_LEFT; |
665 | dir = LEFT; |
| 612 | } else { |
666 | } else { |
| 613 | cur->par->rgt = cur; |
667 | cur->par->rgt = cur; |
| 614 | dir = AVLTREE_RIGHT; |
668 | dir = RIGHT; |
| 615 | } |
669 | } |
| - | 670 | } |
|
| 616 | gpa = cur->par; |
671 | gpa = cur->par; |
| 617 | } else { |
672 | } else { |
| 618 | /* |
673 | /* |
| 619 | * LL rotation. |
674 | * LL rotation. |
| 620 | */ |
675 | */ |
| 621 | 676 | ||
| 622 | gpa->lft = par->rgt; |
677 | gpa->lft = par->rgt; |
| - | 678 | if (par->rgt) |
|
| 623 | if (par->rgt) par->rgt->par = gpa; |
679 | par->rgt->par = gpa; |
| 624 | par->rgt = gpa; |
680 | par->rgt = gpa; |
| 625 | /* |
681 | /* |
| 626 | * Repair paternity. |
682 | * Repair paternity. |
| 627 | */ |
683 | */ |
| 628 | par->par = gpa->par; |
684 | par->par = gpa->par; |
| 629 | gpa->par = par; |
685 | gpa->par = par; |
| 630 | 686 | ||
| 631 | if (par->balance == 0) { |
687 | if (par->balance == 0) { |
| 632 | /* |
688 | /* |
| - | 689 | * The left child of the |
|
| 633 | * Left child of balanced node is balanced, after RR rotation is done, whole |
690 | * balanced node is balanced, |
| - | 691 | * after LL rotation is done, |
|
| 634 | * tree will be balanced. |
692 | * the whole tree will be |
| - | 693 | * balanced. |
|
| 635 | */ |
694 | */ |
| 636 | par->balance = +1; |
695 | par->balance = 1; |
| 637 | gpa->balance = -1; |
696 | gpa->balance = -1; |
| 638 | 697 | ||
| 639 | /* |
698 | /* |
| - | 699 | * Repair the pointer which |
|
| 640 | * Repair pointer which pointed to balanced node and finish balancing. |
700 | * pointed to the balanced node |
| - | 701 | * and finish balancing. |
|
| 641 | */ |
702 | */ |
| 642 | if (par->par == NULL) { |
703 | if (par->par == NULL) { |
| 643 | t->root = par; |
704 | t->root = par; |
| 644 | } else |
705 | } else { |
| 645 | if (par->par->lft == gpa) { |
706 | if (par->par->lft == |
| - | 707 | gpa) { |
|
| 646 | par->par->lft = par; |
708 | par->par->lft = |
| - | 709 | par; |
|
| 647 | } else { |
710 | } else { |
| 648 | par->par->rgt = par; |
711 | par->par->rgt = |
| - | 712 | par; |
|
| 649 | } |
713 | } |
| - | 714 | } |
|
| 650 | break; |
715 | break; |
| 651 | } else { |
716 | } else { |
| 652 | par->balance = gpa->balance = 0; |
717 | par->balance = gpa->balance = 0; |
| 653 | 718 | ||
| 654 | /* |
719 | /* |
| - | 720 | * Repair the pointer which |
|
| - | 721 | * pointed to the balanced node. |
|
| 655 | * Repair pointer which pointed to balanced node. If it was root then balancing |
722 | * If it was root then balancing |
| - | 723 | * is finished. Otherwise |
|
| - | 724 | * continue with the next |
|
| 656 | * is finished else continue in next iteration (parent node). |
725 | * iteration (parent node). |
| 657 | */ |
726 | */ |
| 658 | if (par->par == NULL) { |
727 | if (par->par == NULL) { |
| 659 | t->root = par; |
728 | t->root = par; |
| 660 | break; |
729 | break; |
| 661 | } else { |
730 | } else { |
| 662 | if (par->par->lft == gpa) { //v cyklu jsem ani jednou neskocil - cur nema praveho syna |
731 | if (par->par->lft == |
| - | 732 | gpa) { |
|
| 663 | par->par->lft = par; |
733 | par->par->lft = |
| - | 734 | par; |
|
| 664 | dir = AVLTREE_LEFT; |
735 | dir = LEFT; |
| 665 | } else { |
736 | } else { |
| 666 | par->par->rgt = par; |
737 | par->par->rgt = |
| - | 738 | par; |
|
| 667 | dir = AVLTREE_RIGHT; |
739 | dir = RIGHT; |
| 668 | } |
740 | } |
| 669 | } |
741 | } |
| 670 | } |
742 | } |
| 671 | gpa = par->par; |
743 | gpa = par->par; |
| 672 | } |
744 | } |
| 673 | } else { |
745 | } else { |
| 674 | /* |
746 | /* |
| - | 747 | * Repair the pointer which pointed to the |
|
| 675 | * Repair pointer which pointed to balanced node. If it was root then balancing |
748 | * balanced node. If it was root then balancing |
| 676 | * is finished else continue in next iteration (parent node). |
749 | * is finished. Otherwise continue with the next |
| - | 750 | * iteration (parent node). |
|
| 677 | */ |
751 | */ |
| 678 | if (!gpa->par) break; |
752 | if (!gpa->par) |
| - | 753 | break; |
|
| 679 | 754 | ||
| 680 | if (gpa->par->lft == gpa) { |
755 | if (gpa->par->lft == gpa) { |
| 681 | dir = AVLTREE_LEFT; |
756 | dir = LEFT; |
| 682 | } else { |
757 | } else { |
| 683 | dir = AVLTREE_RIGHT; |
758 | dir = RIGHT; |
| 684 | } |
759 | } |
| 685 | gpa = gpa->par; |
760 | gpa = gpa->par; |
| 686 | } |
761 | } |
| 687 | } |
762 | } |
| 688 | } |
763 | } |
| 689 | } |
764 | } |
| 690 | 765 | ||
| 691 | 766 | ||
| 692 | /** Delete node from AVL tree with the smallest key. |
767 | /** Delete a node with the smallest key from the AVL tree. |
| 693 | * |
768 | * |
| 694 | * @param t AVL tree structure. |
769 | * @param t AVL tree structure. |
| 695 | */ |
770 | */ |
| 696 | bool avltree_delete_min(avltree_t *t) |
771 | bool avltree_delete_min(avltree_t *t) |
| 697 | { |
772 | { |
| 698 | avltree_node_t *node; |
773 | avltree_node_t *node; |
| 699 | 774 | ||
| 700 | /* |
775 | /* |
| 701 | * Start search of smallest key in tree in the root node and |
776 | * Start searching for the smallest key in the tree starting in the root |
| 702 | * continue in cycle to the most left node in the tree which |
777 | * node and continue in cycle to the leftmost node in the tree (which |
| 703 | * must have smallest key. |
778 | * must have the smallest key). |
| 704 | */ |
779 | */ |
| - | 780 | ||
| 705 | node = t->root; |
781 | node = t->root; |
| - | 782 | if (!node) |
|
| 706 | if (!node) return false; |
783 | return false; |
| 707 | 784 | ||
| 708 | while (node->lft != NULL) |
785 | while (node->lft != NULL) |
| 709 | node = node->lft; |
786 | node = node->lft; |
| 710 | 787 | ||
| 711 | /* |
- | |
| 712 | * Use avltree_delete function to delete node from tree. |
- | |
| 713 | */ |
- | |
| 714 | avltree_delete(t,node); |
788 | avltree_delete(t, node); |
| 715 | 789 | ||
| 716 | return true; |
790 | return true; |
| 717 | } |
791 | } |
| - | 792 | ||
| - | 793 | /** @} |
|
| - | 794 | */ |
|