forked from Karnak123/code-leela-2k21
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Spread_Influence.cc
85 lines (65 loc) · 1.59 KB
/
Spread_Influence.cc
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
76
77
78
79
80
81
82
83
84
85
// -*- coding: utf-8 -*-
// Author : Sagnik Mazumder
#include<bits/stdc++.h>
#include<time.h>
using namespace std;
#define ll long long
#define ld long double
#define Fill(s, v) memset(s, v, sizeof(s))
const int MX = 100000;
int n, vis[MX];
vector<pair<int, char>> G[MX];
vector<int> part[3];
bool dfs(int v, int p, char c) {
if (vis[v] != 0) {
// returns false if edge needs to be assigned to two different sets
return vis[v] == p;
}
vis[v] = p;
part[p].push_back(v);
for (auto x : G[v]) {
// if edge colour different from assigning colour, change sets
if (dfs(x.first, x.second == c ? p : p ^ 3, c) == false)
return false;
}
return true;
}
ll solve(char c) {
Fill(vis, 0);
vector<int> ans;
for (int i = 0; i < n; i++)
if (vis[i] == 0) {
part[1].clear();
part[2].clear();
if (dfs(i, 1, c) == false) {
return (n+1);
}
int f = 1;
if (part[2].size() < part[1].size()) f = 2;
ans.insert(ans.end(), part[f].begin(), part[f].end());
}
return (ll)ans.size();
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int m;
cin>>n>>m;
for (int i = 0; i < m; i++) {
int u, v;
char c;
cin>>u>>v>>c;
--u, --v;
G[u].emplace_back(v, c);
G[v].emplace_back(u, c);
}
ll f = solve('A');
ll g = solve('B');
if (g < f) f = g;
if (f > n) {
cout<<-1<<endl;
return 0;
}
cout<<f<<endl;
return(0);
}