P1726-上白泽慧音

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 #define pb push_back
 4 #define _for(i,a,b) for(int i = (a);i < (b);i ++)
 5 #define _rep(i,a,b) for(int i = (a);i > (b);i --)
 6 #define INF 0x3f3f3f3f
 7 #define ll long long
 8 inline ll read()
 9 {
10     ll ans = 0;
11     char ch = getchar(), last = ' ';
12     while(!isdigit(ch)) last = ch, ch = getchar();
13     while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar();
14     if(last == '-') ans = -ans;
15     return ans;
16 }
17 inline void write(ll x)
18 {
19     if(x < 0) x = -x, putchar('-');
20     if(x >= 10) write(x / 10);
21     putchar(x % 10 + '0');
22 }
23 #define maxn 5003
24 int n,m;
25 vector<int> G[maxn];
26 vector<int> rG[maxn];
27 vector<int> vs;
28 vector<int> ans[maxn];
29 bool used[maxn];
30 int V,E;
31 int rnt = 0;
32 void add_edge(int from,int to)
33 {
34     G[from].pb(to);
35     rG[to].pb(from);
36 }
37 void dfs(int v)
38 {
39     used[v] = true;
40     _for(i,0,G[v].size())
41         if(!used[G[v][i]])
42             dfs(G[v][i]);
43     vs.pb(v);
44 }
45 void rdfs(int v,int k)
46 {
47     used[v] = true;
48     ans[k].pb(v);
49     _for(i,0,rG[v].size())
50         if(!used[rG[v][i]])
51             rdfs(rG[v][i],k);
52 }
53 void Kosaraju()
54 {
55     memset(used,0,sizeof(used));
56     _for(v,1,V+1)
57         if(!used[v])
58             dfs(v);
59     
60     memset(used,0,sizeof(used));
61     int k = 0;
62     _rep(i,vs.size()-1,-1)
63         if(!used[vs[i]])
64         {
65             rdfs(vs[i],k);
66             rnt = max(rnt,(int)ans[k].size());
67             k ++;
68         }
69 }
70 int main()
71 {
72     V = read(),E = read();
73     _for(i,1,E+1)
74     {
75         int a,b,t;
76         a = read(),b = read(),t = read();
77         add_edge(a,b);
78         G[a].pb(b);
79         if(2==t)
80             add_edge(b,a);
81     }
82     Kosaraju();
83     _for(i,0,5000)
84         if(ans[i].size()==rnt)
85         {
86             sort(ans[i].begin(),ans[i].end());
87             printf("%d\n",ans[i].size());
88             _for(j,0,ans[i].size())
89                 printf("%d ",ans[i][j]);
90             break;
91         }
92     return 0;
93 }