HDU Meeting

 1 #include <stdio.h>
 2 #include <cstring>
 3 #include <algorithm>
 4 #include <vector>
 5 #include <queue>
 6 using namespace std;
 7 const int maxn = 2000010;
 8 using LL = long long;
 9 using PLI = pair<LL,int>;
10 const LL INF = 0x3f3f3f3f3f3f3f3f;
11 struct arc {
12     int to,next;
13     LL w;
14     arc(int x = 0,LL y = 0,int z = -1) {
15         to = x;
16         w = y;
17         next = z;
18     }
19 } e[8000010];
20 int head[maxn],n,m,tot;
21 vector<int>belong[100010];
22 void add(int u,int v,LL w) {
23     e[tot] = arc(v,w,head[u]);
24     head[u] = tot++;
25 }
26 priority_queue<PLI,vector<PLI>,greater<PLI>>q;
27 bool done[maxn];
28 LL d[2][maxn];
29 void dijkstra(LL d[maxn],int s) {
30     while(!q.empty()) q.pop();
31     q.push(PLI(0,s));
32     d[s] = 0;
33     for(int i = belong[s].size()-1; i >= 0; --i) {
34         d[belong[s][i] + n] = 0;
35         q.push(PLI(0,belong[s][i] + n));
36     }
37     memset(done,false,sizeof done);
38     while(!q.empty()) {
39         int u = q.top().second;
40         q.pop();
41         if(done[u]) continue;
42         done[u] = true;
43         for(int i = head[u]; ~i; i = e[i].next) {
44             if(d[e[i].to] > d[u] + e[i].w) {
45                 d[e[i].to] = d[u] + e[i].w;
46                 q.push(PLI(d[e[i].to],e[i].to));
47             }
48         }
49     }
50 }
51 vector<int>ans;
52 int main() {
53     int kase,cs = 1;
54     scanf("%d",&kase);
55     while(kase--) {
56         scanf("%d%d",&n,&m);
57         memset(head,-1,sizeof head);
58         tot = 0;
59         for(int i = 1; i <= n; ++i) belong[i].clear();
60         for(int i = 1,t,s,tmp; i <= m; ++i) {
61             scanf("%d%d",&t,&s);
62             while(s--) {
63                 scanf("%d",&tmp);
64                 add(n + i,tmp,t);
65                 belong[tmp].push_back(i);
66             }
67         }
68         for(int i = 1; i <= n; ++i)
69             for(auto it:belong[i]) add(i,it + n,0);
70         memset(d,0x3f,sizeof d);
71         dijkstra(d[0],1);
72         dijkstra(d[1],n);
73         LL ret = INF;
74         ans.clear();
75         for(int i = 1; i <= n; ++i) {
76             if(max(d[0][i],d[1][i]) < ret) {
77                 ans.clear();
78                 ans.push_back(i);
79                 ret = max(d[0][i],d[1][i]);
80             } else if(max(d[0][i],d[1][i]) == ret) ans.push_back(i);
81         }
82         if(ret < INF) {
83             printf("Case #%d: %I64d\n",cs++,ret);
84             bool flag = false;
85             for(auto it:ans) {
86                 if(flag) putchar(‘ ‘);
87                 printf("%d",it);
88                 flag = true;
89             }
90             putchar(‘\n‘);
91         } else printf("Case #%d: Evil John\n",cs++);
92     }
93     return 0;
94 }