hdu 1317 XYZZY

http://acm.hdu.edu.cn/showproblem.php?pid=1317

 1 #include <cstdio>
 2 #include <queue>
 3 #include <cstring>
 4 #include <algorithm>
 5 #define maxn 1001
 6 using namespace std;
 7 const int inf=1<<28;
 8 
 9 int dis[maxn];
10 bool vis[maxn];
11 int n,m,x;
12 int a[maxn];
13 bool g[maxn][maxn];
14 int cnt[maxn];
15 
16 bool spfa()
17 {
18     queue<int>q;
19     memset(vis,false,sizeof(vis));
20     memset(cnt,0,sizeof(cnt));
21     for(int i=1; i<=n; i++) dis[i]=0;
22     dis[1]=100;
23     q.push(1);
24     vis[1]=true;
25     while(!q.empty())
26     {
27         int u=q.front();q.pop();
28         vis[u]=false;
29         if(u==n)
30         {
31            return true;
32         }
33         if(cnt[u]==n+1)
34         {
35             continue;
36         }
37         cnt[u]++;
38         if(cnt[u]==n+1)
39         {
40             dis[u]=inf;
41         }
42         for(int i=1; i<=n; i++)
43         {
44             if(g[u][i])
45             {
46                 if(dis[i]<dis[u]+a[i]&&(dis[u]+a[i]>0))
47                 {
48                     dis[i]=dis[u]+a[i];
49                     if(!vis[i])
50                     {
51                         vis[i]=true;
52                         q.push(i);
53                     }
54                 }
55             }
56         }
57     }
58     return false;
59 }
60 
61 int main()
62 {
63     while(scanf("%d",&n)!=EOF)
64     {
65         if(n==-1) break;
66         memset(g,false,sizeof(g));
67         for(int i=1; i<=n; i++)
68         {
69             scanf("%d",&a[i]);
70             scanf("%d",&m);
71             for(int j=0; j<m; j++)
72             {
73                 scanf("%d",&x);
74                 g[i][x]=true;
75             }
76         }
77         if(spfa())
78         {
79             printf("winnable\n");
80         }
81         else
82             printf("hopeless\n");
83     }
84     return 0;
85 }
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posted @ 2014-04-23 14:48  null1019  阅读(183)  评论(0)  编辑  收藏  举报