-
Notifications
You must be signed in to change notification settings - Fork 1
/
UnionFind.cpp
60 lines (51 loc) · 1.09 KB
/
UnionFind.cpp
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
#include <iostream>
#include <vector>
using namespace std;
// reference https://github.com/CyC2018/CS-Notes/blob/master/notes/%E7%AE%97%E6%B3%95%20-%20%E5%B9%B6%E6%9F%A5%E9%9B%86.md
class UnionFind
{
public:
UnionFind(int n) : m_id(n)
{
for (int i = 0; i < n; ++i)
{
m_id[i] = i;
}
}
// user should guareent that a, and b is in range [0, n)
void Union(int aid, int bid)
{
m_id[bid] = aid;
}
// user should guareent that id is in range [0, n)
int FindRootId(int id)
{
while (id != m_id[id])
{
id = m_id[id];
}
return id;
}
// user should guareent that a, and b is in range [0, n)
bool IsConnected(int aid, int bid)
{
return FindRootId(aid) == FindRootId(bid);
}
private:
vector<int> m_id;
};
int main()
{
UnionFind unionfind(1000);
unionfind.Union(0, 100);
unionfind.Union(0, 200);
unionfind.Union(0, 300);
unionfind.Union(0, 400);
unionfind.Union(0, 500);
unionfind.Union(500, 600);
unionfind.Union(500, 700);
unionfind.Union(1, 800);
unionfind.Union(1, 900);
cout << unionfind.IsConnected(200, 800) << endl;
cout << unionfind.IsConnected(200, 700) << endl;
}