1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_UNION_FIND_H
3 #define __LINUX_UNION_FIND_H
4 /**
5  * union_find.h - union-find data structure implementation
6  *
7  * This header provides functions and structures to implement the union-find
8  * data structure. The union-find data structure is used to manage disjoint
9  * sets and supports efficient union and find operations.
10  *
11  * See Documentation/core-api/union_find.rst for documentation and samples.
12  */
13 
14 struct uf_node {
15 	struct uf_node *parent;
16 	unsigned int rank;
17 };
18 
19 /* This macro is used for static initialization of a union-find node. */
20 #define UF_INIT_NODE(node)	{.parent = &node, .rank = 0}
21 
22 /**
23  * uf_node_init - Initialize a union-find node
24  * @node: pointer to the union-find node to be initialized
25  *
26  * This function sets the parent of the node to itself and
27  * initializes its rank to 0.
28  */
uf_node_init(struct uf_node * node)29 static inline void uf_node_init(struct uf_node *node)
30 {
31 	node->parent = node;
32 	node->rank = 0;
33 }
34 
35 /* find the root of a node */
36 struct uf_node *uf_find(struct uf_node *node);
37 
38 /* Merge two intersecting nodes */
39 void uf_union(struct uf_node *node1, struct uf_node *node2);
40 
41 #endif /* __LINUX_UNION_FIND_H */
42