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nuclear@16
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1 #include <stdio.h>
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nuclear@16
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2 #include <stdlib.h>
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nuclear@16
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3 #include <string.h>
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nuclear@16
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4 #include "inttypes.h"
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nuclear@16
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5 #include "rbtree.h"
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6
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7 #define INT2PTR(x) ((void*)(intptr_t)(x))
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8 #define PTR2INT(x) ((int)(intptr_t)(x))
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9
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10 struct rbtree {
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11 struct rbnode *root;
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12
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13 rb_alloc_func_t alloc;
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14 rb_free_func_t free;
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15
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16 rb_cmp_func_t cmp;
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17 rb_del_func_t del;
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18 void *del_cls;
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19
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20 struct rbnode *rstack, *iter;
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21 };
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22
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23 static int cmpaddr(const void *ap, const void *bp);
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24 static int cmpint(const void *ap, const void *bp);
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25
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26 static int count_nodes(struct rbnode *node);
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27 static void del_tree(struct rbnode *node, void (*delfunc)(struct rbnode*, void*), void *cls);
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28 static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data);
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29 static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key);
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30 /*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key);*/
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31 static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls);
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32
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33 struct rbtree *rb_create(rb_cmp_func_t cmp_func)
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34 {
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35 struct rbtree *rb;
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36
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37 if(!(rb = malloc(sizeof *rb))) {
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38 return 0;
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39 }
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40 if(rb_init(rb, cmp_func) == -1) {
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41 free(rb);
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42 return 0;
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43 }
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nuclear@16
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44 return rb;
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45 }
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46
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47 void rb_free(struct rbtree *rb)
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48 {
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49 rb_destroy(rb);
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50 free(rb);
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51 }
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52
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53
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54 int rb_init(struct rbtree *rb, rb_cmp_func_t cmp_func)
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55 {
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56 memset(rb, 0, sizeof *rb);
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57
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58 if(cmp_func == RB_KEY_INT) {
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59 rb->cmp = cmpint;
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60 } else if(cmp_func == RB_KEY_STRING) {
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61 rb->cmp = (rb_cmp_func_t)strcmp;
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62 } else {
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63 rb->cmp = cmpaddr;
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64 }
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65
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66 rb->alloc = malloc;
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67 rb->free = free;
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68 return 0;
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69 }
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70
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71 void rb_destroy(struct rbtree *rb)
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72 {
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73 del_tree(rb->root, rb->del, rb->del_cls);
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74 }
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75
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76 void rb_set_allocator(struct rbtree *rb, rb_alloc_func_t alloc, rb_free_func_t free)
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77 {
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78 rb->alloc = alloc;
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79 rb->free = free;
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80 }
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81
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82
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83 void rb_set_compare_func(struct rbtree *rb, rb_cmp_func_t func)
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84 {
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85 rb->cmp = func;
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86 }
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87
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88 void rb_set_delete_func(struct rbtree *rb, rb_del_func_t func, void *cls)
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89 {
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90 rb->del = func;
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91 rb->del_cls = cls;
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92 }
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93
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94
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95 void rb_clear(struct rbtree *rb)
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96 {
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97 del_tree(rb->root, rb->del, rb->del_cls);
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98 rb->root = 0;
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99 }
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100
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101 int rb_copy(struct rbtree *dest, struct rbtree *src)
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102 {
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103 struct rbnode *node;
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104
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105 rb_clear(dest);
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106 rb_begin(src);
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107 while((node = rb_next(src))) {
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108 if(rb_insert(dest, node->key, node->data) == -1) {
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109 return -1;
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110 }
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111 }
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112 return 0;
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113 }
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114
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115 int rb_size(struct rbtree *rb)
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116 {
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117 return count_nodes(rb->root);
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118 }
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119
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120 int rb_insert(struct rbtree *rb, void *key, void *data)
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121 {
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122 rb->root = insert(rb, rb->root, key, data);
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123 rb->root->red = 0;
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124 return 0;
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125 }
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126
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127 int rb_inserti(struct rbtree *rb, int key, void *data)
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128 {
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129 rb->root = insert(rb, rb->root, INT2PTR(key), data);
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130 rb->root->red = 0;
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131 return 0;
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132 }
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133
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134
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135 int rb_delete(struct rbtree *rb, void *key)
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136 {
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137 rb->root = delete(rb, rb->root, key);
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138 rb->root->red = 0;
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139 return 0;
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140 }
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141
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142 int rb_deletei(struct rbtree *rb, int key)
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143 {
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144 rb->root = delete(rb, rb->root, INT2PTR(key));
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145 rb->root->red = 0;
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146 return 0;
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147 }
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148
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149
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150 struct rbnode *rb_find(struct rbtree *rb, void *key)
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151 {
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152 struct rbnode *node = rb->root;
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153
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154 while(node) {
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155 int cmp = rb->cmp(key, node->key);
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156 if(cmp == 0) {
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157 return node;
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158 }
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159 node = cmp < 0 ? node->left : node->right;
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160 }
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161 return 0;
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162 }
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163
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164 struct rbnode *rb_findi(struct rbtree *rb, int key)
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165 {
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166 return rb_find(rb, INT2PTR(key));
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167 }
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168
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169
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170 void rb_foreach(struct rbtree *rb, void (*func)(struct rbnode*, void*), void *cls)
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171 {
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172 traverse(rb->root, func, cls);
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173 }
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174
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175
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176 struct rbnode *rb_root(struct rbtree *rb)
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177 {
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178 return rb->root;
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179 }
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180
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181 void rb_begin(struct rbtree *rb)
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182 {
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183 rb->rstack = 0;
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184 rb->iter = rb->root;
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185 }
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186
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187 #define push(sp, x) ((x)->next = (sp), (sp) = (x))
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188 #define pop(sp) ((sp) = (sp)->next)
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189 #define top(sp) (sp)
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190
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191 struct rbnode *rb_next(struct rbtree *rb)
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192 {
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193 struct rbnode *res = 0;
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194
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195 while(rb->rstack || rb->iter) {
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196 if(rb->iter) {
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197 push(rb->rstack, rb->iter);
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198 rb->iter = rb->iter->left;
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199 } else {
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200 rb->iter = top(rb->rstack);
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201 pop(rb->rstack);
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202 res = rb->iter;
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203 rb->iter = rb->iter->right;
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204 break;
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205 }
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206 }
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207 return res;
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208 }
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209
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210 void *rb_node_key(struct rbnode *node)
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211 {
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212 return node ? node->key : 0;
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213 }
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214
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215 int rb_node_keyi(struct rbnode *node)
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216 {
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217 return node ? PTR2INT(node->key) : 0;
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218 }
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219
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220 void *rb_node_data(struct rbnode *node)
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221 {
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222 return node ? node->data : 0;
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223 }
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224
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225 static int cmpaddr(const void *ap, const void *bp)
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226 {
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227 return ap < bp ? -1 : (ap > bp ? 1 : 0);
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228 }
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229
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230 static int cmpint(const void *ap, const void *bp)
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231 {
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232 return PTR2INT(ap) - PTR2INT(bp);
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233 }
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234
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235
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nuclear@16
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236 /* ---- left-leaning 2-3 red-black implementation ---- */
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237
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nuclear@16
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238 /* helper prototypes */
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239 static int is_red(struct rbnode *tree);
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240 static void color_flip(struct rbnode *tree);
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241 static struct rbnode *rot_left(struct rbnode *a);
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242 static struct rbnode *rot_right(struct rbnode *a);
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243 static struct rbnode *find_min(struct rbnode *tree);
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244 static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree);
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nuclear@16
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245 /*static struct rbnode *move_red_right(struct rbnode *tree);*/
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246 static struct rbnode *move_red_left(struct rbnode *tree);
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247 static struct rbnode *fix_up(struct rbnode *tree);
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248
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249 static int count_nodes(struct rbnode *node)
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250 {
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251 if(!node)
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252 return 0;
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253
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254 return 1 + count_nodes(node->left) + count_nodes(node->right);
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255 }
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256
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257 static void del_tree(struct rbnode *node, rb_del_func_t delfunc, void *cls)
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258 {
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nuclear@16
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259 if(!node)
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260 return;
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261
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262 del_tree(node->left, delfunc, cls);
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263 del_tree(node->right, delfunc, cls);
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264
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265 if(delfunc) {
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266 delfunc(node, cls);
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267 }
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268 free(node);
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269 }
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270
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nuclear@16
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271 static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data)
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272 {
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273 int cmp;
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274
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275 if(!tree) {
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276 struct rbnode *node = rb->alloc(sizeof *node);
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277 node->red = 1;
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278 node->key = key;
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279 node->data = data;
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280 node->left = node->right = 0;
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281 return node;
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282 }
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283
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284 cmp = rb->cmp(key, tree->key);
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285
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286 if(cmp < 0) {
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287 tree->left = insert(rb, tree->left, key, data);
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288 } else if(cmp > 0) {
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289 tree->right = insert(rb, tree->right, key, data);
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290 } else {
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291 tree->data = data;
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292 }
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293
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nuclear@16
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294 /* fix right-leaning reds */
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295 if(is_red(tree->right)) {
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296 tree = rot_left(tree);
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297 }
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nuclear@16
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298 /* fix two reds in a row */
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299 if(is_red(tree->left) && is_red(tree->left->left)) {
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300 tree = rot_right(tree);
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301 }
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302
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nuclear@16
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303 /* if 4-node, split it by color inversion */
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304 if(is_red(tree->left) && is_red(tree->right)) {
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305 color_flip(tree);
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306 }
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307
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308 return tree;
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309 }
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310
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nuclear@16
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311 static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key)
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312 {
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nuclear@16
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313 int cmp;
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314
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nuclear@16
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315 if(!tree) {
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316 return 0;
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317 }
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318
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319 cmp = rb->cmp(key, tree->key);
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320
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321 if(cmp < 0) {
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322 if(!is_red(tree->left) && !is_red(tree->left->left)) {
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323 tree = move_red_left(tree);
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324 }
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325 tree->left = delete(rb, tree->left, key);
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326 } else {
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nuclear@16
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327 /* need reds on the right */
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328 if(is_red(tree->left)) {
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329 tree = rot_right(tree);
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330 }
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331
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nuclear@16
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332 /* found it at the bottom (XXX what certifies left is null?) */
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333 if(cmp == 0 && !tree->right) {
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334 if(rb->del) {
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335 rb->del(tree, rb->del_cls);
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nuclear@16
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336 }
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337 rb->free(tree);
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nuclear@16
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338 return 0;
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nuclear@16
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339 }
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340
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nuclear@16
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341 if(!is_red(tree->right) && !is_red(tree->right->left)) {
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342 tree = move_red_left(tree);
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nuclear@16
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343 }
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344
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nuclear@16
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345 if(key == tree->key) {
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346 struct rbnode *rmin = find_min(tree->right);
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347 tree->key = rmin->key;
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348 tree->data = rmin->data;
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349 tree->right = del_min(rb, tree->right);
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nuclear@16
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350 } else {
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351 tree->right = delete(rb, tree->right, key);
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352 }
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353 }
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354
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355 return fix_up(tree);
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356 }
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357
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nuclear@16
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358 /*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key)
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359 {
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360 int cmp;
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361
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nuclear@16
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362 if(!node)
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363 return 0;
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364
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365 if((cmp = rb->cmp(key, node->key)) == 0) {
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366 return node;
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367 }
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368 return find(rb, cmp < 0 ? node->left : node->right, key);
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369 }*/
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370
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nuclear@16
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371 static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls)
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372 {
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nuclear@16
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373 if(!node)
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374 return;
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375
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376 traverse(node->left, func, cls);
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377 func(node, cls);
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378 traverse(node->right, func, cls);
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379 }
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380
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nuclear@16
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381 /* helpers */
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382
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nuclear@16
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383 static int is_red(struct rbnode *tree)
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384 {
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nuclear@16
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385 return tree && tree->red;
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nuclear@16
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386 }
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387
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nuclear@16
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388 static void color_flip(struct rbnode *tree)
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nuclear@16
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389 {
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nuclear@16
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390 tree->red = !tree->red;
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nuclear@16
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391 tree->left->red = !tree->left->red;
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nuclear@16
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392 tree->right->red = !tree->right->red;
|
nuclear@16
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393 }
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394
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nuclear@16
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395 static struct rbnode *rot_left(struct rbnode *a)
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nuclear@16
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396 {
|
nuclear@16
|
397 struct rbnode *b = a->right;
|
nuclear@16
|
398 a->right = b->left;
|
nuclear@16
|
399 b->left = a;
|
nuclear@16
|
400 b->red = a->red;
|
nuclear@16
|
401 a->red = 1;
|
nuclear@16
|
402 return b;
|
nuclear@16
|
403 }
|
nuclear@16
|
404
|
nuclear@16
|
405 static struct rbnode *rot_right(struct rbnode *a)
|
nuclear@16
|
406 {
|
nuclear@16
|
407 struct rbnode *b = a->left;
|
nuclear@16
|
408 a->left = b->right;
|
nuclear@16
|
409 b->right = a;
|
nuclear@16
|
410 b->red = a->red;
|
nuclear@16
|
411 a->red = 1;
|
nuclear@16
|
412 return b;
|
nuclear@16
|
413 }
|
nuclear@16
|
414
|
nuclear@16
|
415 static struct rbnode *find_min(struct rbnode *tree)
|
nuclear@16
|
416 {
|
nuclear@16
|
417 if(!tree)
|
nuclear@16
|
418 return 0;
|
nuclear@16
|
419
|
nuclear@16
|
420 while(tree->left) {
|
nuclear@16
|
421 tree = tree->left;
|
nuclear@16
|
422 }
|
nuclear@16
|
423 return tree;
|
nuclear@16
|
424 }
|
nuclear@16
|
425
|
nuclear@16
|
426 static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree)
|
nuclear@16
|
427 {
|
nuclear@16
|
428 if(!tree->left) {
|
nuclear@16
|
429 if(rb->del) {
|
nuclear@16
|
430 rb->del(tree->left, rb->del_cls);
|
nuclear@16
|
431 }
|
nuclear@16
|
432 rb->free(tree->left);
|
nuclear@16
|
433 return 0;
|
nuclear@16
|
434 }
|
nuclear@16
|
435
|
nuclear@16
|
436 /* make sure we've got red (3/4-nodes) at the left side so we can delete at the bottom */
|
nuclear@16
|
437 if(!is_red(tree->left) && !is_red(tree->left->left)) {
|
nuclear@16
|
438 tree = move_red_left(tree);
|
nuclear@16
|
439 }
|
nuclear@16
|
440 tree->left = del_min(rb, tree->left);
|
nuclear@16
|
441
|
nuclear@16
|
442 /* fix right-reds, red-reds, and split 4-nodes on the way up */
|
nuclear@16
|
443 return fix_up(tree);
|
nuclear@16
|
444 }
|
nuclear@16
|
445
|
nuclear@16
|
446 #if 0
|
nuclear@16
|
447 /* push a red link on this node to the right */
|
nuclear@16
|
448 static struct rbnode *move_red_right(struct rbnode *tree)
|
nuclear@16
|
449 {
|
nuclear@16
|
450 /* flipping it makes both children go red, so we have a red to the right */
|
nuclear@16
|
451 color_flip(tree);
|
nuclear@16
|
452
|
nuclear@16
|
453 /* if after the flip we've got a red-red situation to the left, fix it */
|
nuclear@16
|
454 if(is_red(tree->left->left)) {
|
nuclear@16
|
455 tree = rot_right(tree);
|
nuclear@16
|
456 color_flip(tree);
|
nuclear@16
|
457 }
|
nuclear@16
|
458 return tree;
|
nuclear@16
|
459 }
|
nuclear@16
|
460 #endif
|
nuclear@16
|
461
|
nuclear@16
|
462 /* push a red link on this node to the left */
|
nuclear@16
|
463 static struct rbnode *move_red_left(struct rbnode *tree)
|
nuclear@16
|
464 {
|
nuclear@16
|
465 /* flipping it makes both children go red, so we have a red to the left */
|
nuclear@16
|
466 color_flip(tree);
|
nuclear@16
|
467
|
nuclear@16
|
468 /* if after the flip we've got a red-red on the right-left, fix it */
|
nuclear@16
|
469 if(is_red(tree->right->left)) {
|
nuclear@16
|
470 tree->right = rot_right(tree->right);
|
nuclear@16
|
471 tree = rot_left(tree);
|
nuclear@16
|
472 color_flip(tree);
|
nuclear@16
|
473 }
|
nuclear@16
|
474 return tree;
|
nuclear@16
|
475 }
|
nuclear@16
|
476
|
nuclear@16
|
477 static struct rbnode *fix_up(struct rbnode *tree)
|
nuclear@16
|
478 {
|
nuclear@16
|
479 /* fix right-leaning */
|
nuclear@16
|
480 if(is_red(tree->right)) {
|
nuclear@16
|
481 tree = rot_left(tree);
|
nuclear@16
|
482 }
|
nuclear@16
|
483 /* change invalid red-red pairs into a proper 4-node */
|
nuclear@16
|
484 if(is_red(tree->left) && is_red(tree->left->left)) {
|
nuclear@16
|
485 tree = rot_right(tree);
|
nuclear@16
|
486 }
|
nuclear@16
|
487 /* split 4-nodes */
|
nuclear@16
|
488 if(is_red(tree->left) && is_red(tree->right)) {
|
nuclear@16
|
489 color_flip(tree);
|
nuclear@16
|
490 }
|
nuclear@16
|
491 return tree;
|
nuclear@16
|
492 }
|