blob: 946632371d2b701c5a5636bf6e52e6d7b737e8e0 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __UTIL_DISJOINT_SET_H__
#define __UTIL_DISJOINT_SET_H__
#include "util_array.h"
#include <utility>
CCL_NAMESPACE_BEGIN
class DisjointSet {
private:
array<size_t> parents;
array<size_t> ranks;
public:
DisjointSet(size_t size) : parents(size), ranks(size)
{
for (size_t i = 0; i < size; i++) {
parents[i] = i;
ranks[i] = 0;
}
}
size_t find(size_t x)
{
size_t root = x;
while (parents[root] != root) {
root = parents[root];
}
while (parents[x] != root) {
size_t parent = parents[x];
parents[x] = root;
x = parent;
}
return root;
}
void join(size_t x, size_t y)
{
size_t x_root = find(x);
size_t y_root = find(y);
if (x_root == y_root) {
return;
}
if (ranks[x_root] < ranks[y_root]) {
std::swap(x_root, y_root);
}
parents[y_root] = x_root;
if (ranks[x_root] == ranks[y_root]) {
ranks[x_root]++;
}
}
};
CCL_NAMESPACE_END
#endif /* __UTIL_DISJOINT_SET_H__ */
|
