linux内核中有个rbtree,stl源码中也有，标准stl中的map和set都只是包装了下rbtree
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1 /************************************************************* 2 * 作者:陈新 3 * 邮箱:cx2pirate@gmail.com 4 * 时间:2014.6.1 5 * 环境:gcc 6 * 参考:《算法导论》 7 * ***********************************************************/ 8 9 10 #ifndef _HEADER_RB_TREE_ 11 #define _HEADER_RB_TREE_ 12 13 typedef int Key; //键值类型 14 typedef int Data; //其他数据 15 typedef enum{BLACK,RED} RB_COLOR; 16 17 struct rb_node{ 18 struct rb_node *parent; 19 struct rb_node *right; 20 struct rb_node *left; 21 RB_COLOR color; 22 Key key; //键值 23 Data data; //数据域 24 }; 25 26 27 struct rb_root{ 28 struct rb_node * rb_node; 29 }; 30 31 extern struct rb_node *RB_NIL; 32 #define rb_parent(r) ((struct rb_node *)((r) ->parent)) 33 #define RB_ROOT (struct rb_root){RB_NIL} 34 35 //插入和删除节点 36 int rb_insert(struct rb_node *,struct rb_root*); 37 struct rb_node * rb_delete(struct rb_node *,struct rb_root*); //只把node从树上卸下来，并没有释放空间 38 struct rb_node * rb_search(Key key,struct rb_root*); 39 40 /************************************************************** 41 *和二叉树相同,暂时没有实现,rbtree.c中有几个和下面作用相同的函数 42 *这里时kernel/include/linux/rbtree.h中的声明... 43 * ***********************************************************/ 44 45 //查找前趋和后继节点 46 struct rb_node *rb_next(const struct rb_node*); 47 struct rb_node *rb_prev(const struct rb_node*); 48 struct rb_node *rb_first(const struct rb_node*); 49 struct rb_node *rb_last(const struct rb_node*); 50 51 //后续遍历 52 struct rb_node *rb_first_postorder(const struct rb_root*); 53 struct rb_node *rb_next_postorder(const struct rb_node*); 54 55 //快速替换某个节点 56 void rb_replace_node(struct rb_node *victim,struct rb_node *new,struct rb_root *root); 57 58 #endif 59 60 61 #include "rbtree.h" 62 #include <stdio.h> 63 64 struct rb_node *RB_NIL = &(struct rb_node){0,0,0,BLACK,0,0}; 65 66 //node为树内任意右孩子不为RB_NIL的节点 67 void left_rotate(struct rb_node *node,struct rb_root *root) 68 { 69 struct rb_node *rc = node ->right; //rc为node的right child 70 node ->right = rc ->left; 71 72 if(rc ->left != RB_NIL){ 73 rc ->left ->parent = node; 74 } 75 76 rc ->parent = node ->parent; 77 if(node ->parent == RB_NIL){ //node为root节点 78 root ->rb_node = rc; 79 } 80 else if(node == node ->parent ->left){ 81 node ->parent ->left = rc; 82 } 83 else{ 84 node ->parent ->right = rc; 85 } 86 87 rc ->left = node; 88 node ->parent = rc; 89 } 90 91 //node为树内任意左孩子不为RB_NIL的节点 92 void right_rotate(struct rb_node *node,struct rb_root *root) 93 { 94 struct rb_node *lc = node ->left; //lc为node的left child 95 node ->left = lc ->righ 96 if(lc ->right != RB_NIL){ //刚开始直接copy过来,少改了个left,debug long long time... 97 lc ->right ->parent = node; 98 } 99 100 lc ->parent = node ->parent; 101 if(node ->parent == RB_NIL){ //node为root节点 102 root ->rb_node = lc; 103 } 104 else if(node == node ->parent ->left){ 105 node ->parent ->left = lc; 106 } 107 else{ 108 node ->parent ->right = lc; 109 } 110 111 lc ->right = node; 112 node ->parent = lc; 113 } 114 115 //非递归版本二叉树查找 116 //node为根节点,k为键值 117 //返回k节点指针,如果不存在返回RB_NIL 118 struct rb_node *rb_search(Key key,struct rb_root *root) 119 { 120 struct rb_node *p = root ->rb_node; 121 122 while(p != RB_NIL && key != p -> key) 123 { 124 p = key < p ->key ? p ->left : p ->right; 125 } 126 127 return p == RB_NIL ? NULL : p; 128 } 129 130 //返回以node为根的子树的最小节点 131 struct rb_node *rb_minimum(struct rb_node *node) 132 { 133 struct rb_node *p = node; 134 135 while(p ->left != RB_NIL) 136 { 137 p = p ->left; 138 } 139 140 return p; 141 } 142 143 //返回以node为根的子树的最大节点 144 struct rb_node *rb_maximum(struct rb_node *node) 145 { 146 struct rb_node *p = node; 147 148 while(p ->right != RB_NIL) 149 { 150 p = p ->right; 151 } 152 153 return p; 154 } 155 156 //返回node的后继节点 157 struct rb_node *tree_successor(struct rb_node *node) 158 { 159 struct rb_node *p = node; 160 161 if(p ->right != RB_NIL) 162 { 163 return rb_minimum(p ->right); 164 } 165 166 struct rb_node *parent = p ->parent; 167 while(parent != RB_NIL && p == parent ->right) 168 { 169 p = parent; 170 parent = parent ->parent; 171 } 172 173 return parent; 174 } 175 176 //插入节点后红黑树别破坏的性质2和性质4 177 void rb_insert_fixup(struct rb_node *node,struct rb_root *root) 178 { 179 while((rb_parent(node)) ->color == RED){ 180 if(rb_parent(node) == rb_parent(rb_parent(node)) ->left){ 181 struct rb_node *uc = rb_parent(rb_parent(node)) ->right; 182 if(uc ->color == RED){ //case1:叔叔的颜色也为红色 183 uc ->color = BLACK; 184 rb_parent(node) ->color = BLACK; 185 rb_parent(rb_parent(node)) ->color = RED; 186 node = rb_parent(rb_parent(node)); 187 } 188 else{ 189 if(node == rb_parent(node) ->right){ //case2:叔叔为黑色,node为parent的右节点 190 node = rb_parent(node); //通过左旋变为case3 191 left_rotate(node,root); 192 } 193 194 rb_parent(node) ->color = BLACK; 195 rb_parent(rb_parent(node)) ->color = RED; 196 right_rotate(rb_parent(rb_parent(node)),root); 197 } 198 } 199 else{ 200 struct rb_node *uc = rb_parent(rb_parent(node)) ->left; 201 if(uc ->color == RED){ //case1:叔叔的颜色也为红色 202 uc ->color = BLACK; 203 rb_parent(node) ->color = BLACK; 204 rb_parent(rb_parent(node)) ->color = RED; 205 node = rb_parent(rb_parent(node)); 206 } 207 else{ 208 if(node == rb_parent(node) ->left){ //case2:叔叔为黑色,node为parent的右节点 209 node = rb_parent(node); //通过左旋变为case3 210 right_rotate(node,root); 211 } 212 213 rb_parent(node) ->color = BLACK; 214 rb_parent(rb_parent(node)) ->color = RED; 215 left_rotate(rb_parent(rb_parent(node)),root); 216 } 217 } 218 } 219 root ->rb_node ->color = BLACK; 220 } 221 222 //插入一个节点,与二叉树区别不大,最后需要调用rb_insert_fixup修复红黑性质 223 int rb_insert(struct rb_node *node,struct rb_root *root) 224 { 225 struct rb_node *parent = RB_NIL; //node在树中的父亲 226 struct rb_node *p = root ->rb_node; 227 228 while(p != RB_NIL){ 229 parent = p; 230 if(node ->key < p ->key){ 231 p = p ->left; 232 } 233 else if(node ->key > p ->key){ 234 p = p ->right; 235 } 236 else{ 237 return 0; 238 } 239 } 240 241 node ->parent = parent; 242 if(parent == RB_NIL){ 243 root ->rb_node = node; 244 } 245 else if(node ->key < parent ->key){ 246 parent ->left = node; 247 } 248 else{ 249 parent ->right = node; 250 } 251 252 node ->left = RB_NIL; 253 node ->right = RB_NIL; 254 node ->color = RED; 255 256 rb_insert_fixup(node,root); 257 return 0; 258 } 259 260 void rb_delete_fixup(struct rb_node *node,struct rb_root *root) 261 { 262 struct rb_node *sibiling; 263 while(node != root ->rb_node && node ->color == BLACK){ //node has double black attrubute 264 if(node == rb_parent(node) ->left){ //!note:node could be RB_NIL 265 sibiling = rb_parent(node) ->right; //!note:double black node certainly has a brother 266 267 if(sibiling ->color == RED){ //case 1:brother's color is red 268 sibiling ->color = BLACK; //and sibiling has two black child 269 rb_parent(node) ->color = RED; //aparenter this,case 1 will be turned to 270 left_rotate(rb_parent(node),root); //case2,case 3 or case 4. 271 sibiling = rb_parent(node) ->right; 272 } 273 274 if(sibiling ->left ->color == BLACK && sibiling ->right ->color == BLACK){ 275 sibiling ->color = RED; 276 node = rb_parent(node); //case 2:双重黑色上移到父亲，循环迭代. 277 } 278 else{ 279 if(sibiling ->right ->color == BLACK){ //case 3:变为case 4 280 sibiling ->left ->color = BLACK; 281 sibiling ->color = RED; 282 right_rotate(sibiling,root); 283 sibiling = rb_parent(node) ->right; 284 } 285 286 sibiling ->color = rb_parent(node) ->color; //case 4: 287 rb_parent(node) ->color = BLACK; 288 sibiling ->right ->color = BLACK; 289 left_rotate(rb_parent(node),root); 290 node = root ->rb_node; //case 4经过此步就结束了 291 } 292 } 293 else{ 294 sibiling = rb_parent(node) ->left; //double black node certainly has a brother 295 296 if(sibiling ->color == RED){ //case 1:brother's color is red 297 sibiling ->color = BLACK; //and sibiling has two black child 298 rb_parent(node) ->color = RED; //aparenter this,case 1 will be turned to 299 right_rotate(rb_parent(node),root); //case2,case 3 or case 4. 300 sibiling = rb_parent(node) ->left; 301 } 302 303 if(sibiling ->left ->color == BLACK && sibiling ->right ->color == BLACK){ 304 sibiling ->color = RED; 305 node = rb_parent(node); //case 2:double black move up. 306 } 307 else{ 308 if(sibiling ->left ->color == BLACK){ //case 3: 309 sibiling ->right ->color = BLACK; 310 sibiling ->color = RED; 311 left_rotate(sibiling,root); 312 sibiling = rb_parent(node) ->left; 313 } 314 315 sibiling ->color = rb_parent(node) ->color; //case 4: 316 rb_parent(node) ->color = BLACK; 317 sibiling ->left ->color = BLACK; 318 right_rotate(rb_parent(node),root); 319 node = root ->rb_node; //case 4经过此步就结束了 320 } 321 } 322 } 323 324 node ->color = BLACK; 325 } 326 327 struct rb_node * rb_delete(struct rb_node *node,struct rb_root *root) 328 { 329 struct rb_node *p,*ps; //p为待删除节点,ps为p的子节点 330 if(node ->left == RB_NIL || node -> right == RB_NIL){ 331 p = node; 332 } 333 else{ 334 p = tree_successor(node); 335 } 336 337 ps = p ->left != RB_NIL ? p ->left : p ->right; 338 ps ->parent = p ->parent; //different from binary_tree,ps could be NIL 339 340 if(p ->parent == RB_NIL){ 341 root ->rb_node = ps; 342 } 343 else if(p == rb_parent(p) ->left){ 344 rb_parent(p) ->left = ps; 345 } 346 else{ 347 rb_parent(p) ->right = ps; 348 } 349 350 if(p != node){ //复制key域,如果还有其它数据需要一同复制{ 351 node ->key = p ->key; 352 node ->data = p ->data; 353 } 354 355 if(p ->color == BLACK){ //black node is deleted 356 rb_delete_fixup(ps,root); 357 } 358 359 return p; 360 }
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