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https://github.com/jart/cosmopolitan.git
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Implement new red-black tree
This commit is contained in:
Justine Tunney
parent
fc65422660
commit
3756870635
3 changed files with 494 additions and 0 deletions
312
libc/intrin/rbtree.c
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312
libc/intrin/rbtree.c
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// Copyright 2024 Justine Alexandra Roberts Tunney
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//
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// Permission to use, copy, modify, and/or distribute this software for
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// any purpose with or without fee is hereby granted, provided that the
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// above copyright notice and this permission notice appear in all copies.
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//
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// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
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// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
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// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
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// AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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// DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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// PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
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// TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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// PERFORMANCE OF THIS SOFTWARE.
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#include "rbtree.h"
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#include "libc/dce.h"
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#include "libc/str/str.h"
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#define RBTREE_DEBUG
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struct rbtree *rbtree_next(struct rbtree *node) {
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if (!node)
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return 0;
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if (node->right)
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return rbtree_first(node->right);
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struct rbtree *parent = node->parent;
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while (parent && node == parent->right) {
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node = parent;
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parent = parent->parent;
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}
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return parent;
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}
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struct rbtree *rbtree_prev(struct rbtree *node) {
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if (!node)
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return 0;
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if (rbtree_get_left(node))
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return rbtree_last(rbtree_get_left(node));
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struct rbtree *parent = node->parent;
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while (parent && node == rbtree_get_left(parent)) {
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node = parent;
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parent = parent->parent;
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}
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return parent;
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}
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struct rbtree *rbtree_first(struct rbtree *node) {
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while (node && rbtree_get_left(node))
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node = rbtree_get_left(node);
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return node;
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}
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struct rbtree *rbtree_last(struct rbtree *node) {
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while (node && node->right)
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node = node->right;
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return node;
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}
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static void rbtree_rotate_left(struct rbtree **root, struct rbtree *x) {
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struct rbtree *y = x->right;
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x->right = rbtree_get_left(y);
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if (rbtree_get_left(y))
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rbtree_get_left(y)->parent = x;
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y->parent = x->parent;
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if (!x->parent) {
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*root = y;
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} else if (x == rbtree_get_left(x->parent)) {
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rbtree_set_left(x->parent, y);
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} else {
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x->parent->right = y;
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}
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rbtree_set_left(y, x);
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x->parent = y;
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}
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static void rbtree_rotate_right(struct rbtree **root, struct rbtree *y) {
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struct rbtree *x = rbtree_get_left(y);
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rbtree_set_left(y, x->right);
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if (x->right)
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x->right->parent = y;
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x->parent = y->parent;
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if (!y->parent) {
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*root = x;
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} else if (y == y->parent->right) {
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y->parent->right = x;
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} else {
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rbtree_set_left(y->parent, x);
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}
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x->right = y;
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y->parent = x;
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}
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static void rbtree_insert_fixup(struct rbtree **root, struct rbtree *node) {
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rbtree_set_red(node, 1);
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while (node != *root && rbtree_get_red(node->parent)) {
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if (node->parent == rbtree_get_left(node->parent->parent)) {
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struct rbtree *uncle = node->parent->parent->right;
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if (uncle && rbtree_get_red(uncle)) {
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rbtree_set_red(node->parent, 0);
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rbtree_set_red(uncle, 0);
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rbtree_set_red(node->parent->parent, 1);
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node = node->parent->parent;
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} else {
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if (node == node->parent->right) {
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node = node->parent;
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rbtree_rotate_left(root, node);
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}
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rbtree_set_red(node->parent, 0);
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rbtree_set_red(node->parent->parent, 1);
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rbtree_rotate_right(root, node->parent->parent);
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}
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} else {
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struct rbtree *uncle = rbtree_get_left(node->parent->parent);
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if (uncle && rbtree_get_red(uncle)) {
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rbtree_set_red(node->parent, 0);
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rbtree_set_red(uncle, 0);
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rbtree_set_red(node->parent->parent, 1);
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node = node->parent->parent;
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} else {
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if (node == rbtree_get_left(node->parent)) {
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node = node->parent;
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rbtree_rotate_right(root, node);
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}
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rbtree_set_red(node->parent, 0);
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rbtree_set_red(node->parent->parent, 1);
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rbtree_rotate_left(root, node->parent->parent);
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}
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}
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}
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rbtree_set_red(*root, 0);
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}
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void rbtree_insert(struct rbtree **root, struct rbtree *node,
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rbtree_cmp_f *cmp) {
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bzero(node, sizeof(*node));
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if (!*root) {
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*root = node;
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} else {
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struct rbtree *search = *root;
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struct rbtree *parent = 0;
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do {
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parent = search;
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if (cmp(node, search) < 0) {
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search = rbtree_get_left(search);
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} else {
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search = search->right;
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}
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} while (search);
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if (cmp(node, parent) < 0) {
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rbtree_set_left(parent, node);
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} else {
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parent->right = node;
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}
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node->parent = parent;
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rbtree_insert_fixup(root, node);
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}
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}
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static void rbtree_transplant(struct rbtree **root, struct rbtree *u,
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struct rbtree *v) {
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if (!u->parent) {
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*root = v;
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} else if (u == rbtree_get_left(u->parent)) {
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rbtree_set_left(u->parent, v);
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} else {
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u->parent->right = v;
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}
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if (v)
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v->parent = u->parent;
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}
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static void rbtree_remove_fixup(struct rbtree **root, struct rbtree *node,
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struct rbtree *parent) {
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while (node != *root && (!node || !rbtree_get_red(node))) {
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if (node == rbtree_get_left(parent)) {
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struct rbtree *sibling = parent->right;
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if (rbtree_get_red(sibling)) {
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rbtree_set_red(sibling, 0);
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rbtree_set_red(parent, 1);
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rbtree_rotate_left(root, parent);
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sibling = parent->right;
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}
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if ((!rbtree_get_left(sibling) ||
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!rbtree_get_red(rbtree_get_left(sibling))) &&
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(!sibling->right || !rbtree_get_red(sibling->right))) {
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rbtree_set_red(sibling, 1);
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node = parent;
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parent = node->parent;
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} else {
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if (!sibling->right || !rbtree_get_red(sibling->right)) {
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rbtree_set_red(rbtree_get_left(sibling), 0);
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rbtree_set_red(sibling, 1);
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rbtree_rotate_right(root, sibling);
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sibling = parent->right;
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}
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rbtree_set_red(sibling, rbtree_get_red(parent));
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rbtree_set_red(parent, 0);
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rbtree_set_red(sibling->right, 0);
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rbtree_rotate_left(root, parent);
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node = *root;
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break;
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}
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} else {
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struct rbtree *sibling = rbtree_get_left(parent);
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if (rbtree_get_red(sibling)) {
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rbtree_set_red(sibling, 0);
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rbtree_set_red(parent, 1);
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rbtree_rotate_right(root, parent);
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sibling = rbtree_get_left(parent);
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}
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if ((!sibling->right || !rbtree_get_red(sibling->right)) &&
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(!rbtree_get_left(sibling) ||
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!rbtree_get_red(rbtree_get_left(sibling)))) {
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rbtree_set_red(sibling, 1);
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node = parent;
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parent = node->parent;
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} else {
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if (!rbtree_get_left(sibling) ||
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!rbtree_get_red(rbtree_get_left(sibling))) {
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rbtree_set_red(sibling->right, 0);
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rbtree_set_red(sibling, 1);
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rbtree_rotate_left(root, sibling);
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sibling = rbtree_get_left(parent);
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}
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rbtree_set_red(sibling, rbtree_get_red(parent));
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rbtree_set_red(parent, 0);
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rbtree_set_red(rbtree_get_left(sibling), 0);
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rbtree_rotate_right(root, parent);
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node = *root;
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break;
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}
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}
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}
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if (node)
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rbtree_set_red(node, 0);
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}
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void rbtree_remove(struct rbtree **root, struct rbtree *node) {
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struct rbtree *y = node;
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struct rbtree *x = 0;
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struct rbtree *x_parent = 0;
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int y_original_color = rbtree_get_red(y);
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if (!rbtree_get_left(node)) {
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x = node->right;
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rbtree_transplant(root, node, node->right);
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x_parent = node->parent;
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} else if (!node->right) {
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x = rbtree_get_left(node);
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rbtree_transplant(root, node, rbtree_get_left(node));
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x_parent = node->parent;
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} else {
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y = rbtree_first(node->right);
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y_original_color = rbtree_get_red(y);
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x = y->right;
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if (y->parent == node) {
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if (x)
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x->parent = y;
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x_parent = y;
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} else {
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rbtree_transplant(root, y, y->right);
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y->right = node->right;
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y->right->parent = y;
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x_parent = y->parent;
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}
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rbtree_transplant(root, node, y);
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rbtree_set_left(y, rbtree_get_left(node));
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rbtree_get_left(y)->parent = y;
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rbtree_set_red(y, rbtree_get_red(node));
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}
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if (!y_original_color)
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rbtree_remove_fixup(root, x, x_parent);
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}
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struct rbtree *rbtree_get(const struct rbtree *node, const struct rbtree *key,
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rbtree_cmp_f *cmp) {
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while (node) {
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int c = cmp(key, node);
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if (c < 0) {
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node = rbtree_get_left(node);
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} else if (c > 0) {
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node = node->right;
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} else {
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return (struct rbtree *)node;
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}
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}
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return 0;
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}
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struct rbtree *rbtree_floor(const struct rbtree *node, const struct rbtree *key,
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rbtree_cmp_f *cmp) {
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while (node) {
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if (cmp(key, node) < 0) {
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node = rbtree_get_left(node);
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} else {
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node = node->right;
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}
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}
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return (struct rbtree *)node;
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}
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struct rbtree *rbtree_ceil(const struct rbtree *node, const struct rbtree *key,
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rbtree_cmp_f *cmp) {
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while (node) {
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if (cmp(node, key) < 0) {
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node = rbtree_get_left(node);
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} else {
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node = node->right;
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}
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}
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return (struct rbtree *)node;
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}
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57
libc/intrin/rbtree.h
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57
libc/intrin/rbtree.h
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#ifdef _COSMO_SOURCE
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#ifndef COSMOPOLITAN_RBTREE_H_
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#define COSMOPOLITAN_RBTREE_H_
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#define rbtree_ceil __rbtree_ceil
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#define rbtree_first __rbtree_first
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#define rbtree_floor __rbtree_floor
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#define rbtree_get __rbtree_get
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#define rbtree_insert __rbtree_insert
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#define rbtree_last __rbtree_last
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#define rbtree_next __rbtree_next
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#define rbtree_prev __rbtree_prev
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#define rbtree_remove __rbtree_remove
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COSMOPOLITAN_C_START_
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#define RBTREE_CONTAINER(t, f, p) ((t *)(((char *)(p)) - offsetof(t, f)))
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struct rbtree {
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uintptr_t word;
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struct rbtree *right;
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struct rbtree *parent;
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};
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typedef int rbtree_cmp_f(const struct rbtree *, const struct rbtree *);
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static inline struct rbtree *rbtree_get_left(const struct rbtree *node) {
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return (struct rbtree *)(node->word & -2);
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}
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static inline void rbtree_set_left(struct rbtree *node, struct rbtree *left) {
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node->word = (uintptr_t)left | (node->word & 1);
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}
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static inline int rbtree_get_red(const struct rbtree *node) {
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return node->word & 1;
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}
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static inline void rbtree_set_red(struct rbtree *node, int red) {
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node->word &= -2;
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node->word |= red;
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}
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struct rbtree *rbtree_next(struct rbtree *) libcesque;
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struct rbtree *rbtree_prev(struct rbtree *) libcesque;
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struct rbtree *rbtree_first(struct rbtree *) libcesque;
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struct rbtree *rbtree_last(struct rbtree *) libcesque;
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void rbtree_remove(struct rbtree **, struct rbtree *) libcesque;
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void rbtree_insert(struct rbtree **, struct rbtree *, rbtree_cmp_f *) libcesque;
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struct rbtree *rbtree_get(const struct rbtree *, const struct rbtree *,
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rbtree_cmp_f *) libcesque;
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struct rbtree *rbtree_ceil(const struct rbtree *, const struct rbtree *,
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rbtree_cmp_f *) libcesque;
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struct rbtree *rbtree_floor(const struct rbtree *, const struct rbtree *,
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rbtree_cmp_f *) libcesque;
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COSMOPOLITAN_C_END_
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#endif /* COSMOPOLITAN_RBTREE_H_ */
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#endif /* _COSMO_SOURCE */
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