sys: Add Disjoint-set (union-find) data structure #93300
+167
−0
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
rruuaanng
changed the title
jukkar
reviewed
Jul 18, 2025
rruuaanng
force-pushed
the
add-uf
branch
2 times, most recently
from
f37ab3c to
8583e82
Compare
kartben
reviewed
Jul 23, 2025
kartben
reviewed
Jul 23, 2025
andyross
reviewed
Jul 23, 2025
include/zephyr/sys/uf.h
Outdated
| */ | ||
| struct uf_node { | ||
| /** @cond INTERNAL_HIDDEN */ | ||
| struct uf_node *parent; |
There was a problem hiding this comment.
This looks suspiciously like an slist, no? Not like linked list handling is that big a deal, but every byte of code savings helps.
rruuaanng
force-pushed
the
add-uf
branch
2 times, most recently
from
de9abc2 to
f7d79b5
Compare
pdgendt
reviewed
Jul 25, 2025
cfriedt
reviewed
Jul 26, 2025
cfriedt
requested changes
Jul 26, 2025
There was a problem hiding this comment.
@rruuaanng - please also add a testcase.yaml file.
It may be worth it to add incremental tests to each iteration in the one test function to validate certain assumptions about the disjoint set.
E.g. rank at each stage, parent properties, and so on.
Comment on lines
17
to
35
| ZTEST(set, test_find_and_union) | ||
| { | ||
| sys_set_makeset(&data_list[0].ufnode, 5); | ||
| sys_set_makeset(&data_list[1].ufnode, 4); | ||
| sys_set_makeset(&data_list[2].ufnode, 3); | ||
| sys_set_makeset(&data_list[3].ufnode, 2); | ||
| sys_set_makeset(&data_list[4].ufnode, 1); | ||
|
|
||
| sys_set_union(&data_list[0].ufnode, &data_list[1].ufnode); | ||
| sys_set_union(&data_list[1].ufnode, &data_list[2].ufnode); | ||
| sys_set_union(&data_list[2].ufnode, &data_list[3].ufnode); | ||
| sys_set_union(&data_list[3].ufnode, &data_list[4].ufnode); | ||
|
|
||
| struct sys_set_node *root_node = sys_set_find(&data_list[4].ufnode); | ||
| struct user_data *root_data = CONTAINER_OF(root_node, struct user_data, ufnode); | ||
|
|
||
| zassert_equal(root_data->n, data_list[0].n, "Root set data n are not equal"); | ||
| zassert_equal(root_data->ufnode.rank, root_node->rank, "Root set are not equal"); | ||
| } |
There was a problem hiding this comment.
You will need to rename ufnode to node everywhere
Add a set of Disjoint-set functions (`find`, `union`) to handle queries between sets. Signed-off-by: James Roy <[email protected]>
Add unit tests for functions (`sys_set_makeset`, `sys_set_union` and `sys_set_find`). Signed-off-by: James Roy <[email protected]>
|
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Add a set of Disjoint-set functions (
find,union) to handle queries between sets.