mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-06-27 14:58:30 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Implement new red-black tree

Browse source
This commit is contained in:
Justine Tunney 2024-07-05 12:56:03 -07:00
parent fc65422660
commit 3756870635
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
3 changed files with 494 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

125
test/libc/intrin/rbtree_test.c Normal file
View file

@ -0,0 +1,125 @@
// Copyright 2024 Justine Alexandra Roberts Tunney
//
// Permission to use, copy, modify, and/or distribute this software for
// any purpose with or without fee is hereby granted, provided that the
// above copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
// AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
// DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
// PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
// TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
#include "libc/intrin/rbtree.h"
#include "libc/intrin/kprintf.h"
#include "libc/macros.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/rand.h"
#define NUMBER_CONTAINER(e) RBTREE_CONTAINER(struct number, elem, e)
void rbtree_checker(const struct rbtree *node, const struct rbtree *parent,
int black_count, int *black_height, rbtree_cmp_f *cmp) {
if (!node) {
// Leaf nodes are considered black
if (*black_height == -1) {
*black_height = black_count;
} else if (black_count != *black_height) {
// ILLEGAL TREE: Black height mismatch
__builtin_trap();
}
return;
}
if (node->parent != parent)
// ILLEGAL TREE: Parent link is incorrect
__builtin_trap();
if (parent) {
if (rbtree_get_left(parent) == node && cmp(parent, node) < 0)
// ILLEGAL TREE: Binary search property violated on left child
__builtin_trap();
if (parent->right == node && cmp(node, parent) < 0)
// ILLEGAL TREE: Binary search property violated on right child
__builtin_trap();
}
if (!rbtree_get_red(node)) {
black_count++;
} else if (parent && rbtree_get_red(parent)) {
// ILLEGAL TREE: Red node has red child
__builtin_trap();
}
rbtree_checker(rbtree_get_left(node), node, black_count, black_height, cmp);
rbtree_checker(node->right, node, black_count, black_height, cmp);
}
void rbtree_check(struct rbtree *root, rbtree_cmp_f *cmp) {
if (root) {
if (rbtree_get_red(root))
// ILLEGAL TREE: root node must be black
__builtin_trap();
int black_height = -1;
rbtree_checker(root, 0, 0, &black_height, cmp);
}
}
struct number {
int number;
struct rbtree elem;
};
int number_compare(const struct rbtree *ra, const struct rbtree *rb) {
const struct number *a = NUMBER_CONTAINER(ra);
const struct number *b = NUMBER_CONTAINER(rb);
return (a->number > b->number) - (a->number < b->number);
}
struct number *number_new(int number) {
static int used;
static struct number heap[8192];
if (used == ARRAYLEN(heap))
return 0;
struct number *res = &heap[used++];
res->number = number;
return res;
}
struct rbtree *tree = 0;
void print(void) {
for (struct rbtree *e = rbtree_first(tree); e; e = rbtree_next(e))
kprintf("%3d", NUMBER_CONTAINER(e)->number);
kprintf("\n");
}
void print_reversed(void) {
for (struct rbtree *e = rbtree_last(tree); e; e = rbtree_prev(e))
kprintf("%3d", NUMBER_CONTAINER(e)->number);
kprintf("\n");
}
void simple_test(void) {
static const int kNumba[] = {74, 53, 96, 70, 34, 95, 30, 2, 89, 46,
23, 2, 52, 0, 34, 12, 90, 95, 32, 65};
for (int i = 0; i < 20; ++i) {
int number = kNumba[i];
kprintf("%3d", number);
rbtree_insert(&tree, &number_new(number)->elem, number_compare);
rbtree_check(tree, number_compare);
}
kprintf("\n");
print();
print_reversed();
for (int i = 0; i < 20; ++i) {
rbtree_remove(&tree, rbtree_get(tree, &(&(struct number){kNumba[i]})->elem,
number_compare));
rbtree_check(tree, number_compare);
print();
}
}
int main() {
ShowCrashReports();
simple_test();
}