[题解]UVA658 It's not a Bug, it's a Feature!

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <queue>
 5 using namespace std;
 6 #define MaxM 120
 7 #define MaxN 30
 8 int Cost[MaxM],Condition[MaxM][5],Operate[MaxM][5];
 9 char s1[MaxN],s2[MaxN];
10 bool vis[(1<<20)+20];
11 int n,m,ans;
12 bool Sol;
13 typedef pair<int, int> p;
14 struct cmp
15 {
16     bool operator()(p a,p b)
17     {
18         return a.first>b.first;
19     }
20 };
21 priority_queue <p, vector<p>, cmp> q;
22 inline void Clean()
23 {
24     memset(Condition,0,sizeof(Condition));
25     memset(Operate,0,sizeof(Operate));
26     Sol=false;
27     memset(vis,false,sizeof(vis));
28     while(!q.empty())
29         q.pop();
30 }
31 void Bfs()
32 {
33     q.push(make_pair(0,(1<<n)-1));
34     p u;
35     int i,fi,Cur;
36     while(!q.empty())
37     {
38         u=q.top();q.pop();
39         fi=u.first;Cur=u.second;
40         if(!Cur)
41         {
42             Sol=true;
43             ans=fi;
44             return;
45         }
46         if(vis[Cur])
47             continue;
48         vis[Cur]=true;
49         for(i=1;i<=m;++i)
50         {
51             Cur=u.second;
52             if((Cur&Condition[i][0])==Condition[i][0]&&((~Cur)&Condition[i][1])==Condition[i][1])
53             {
54                 Cur|=Operate[i][0];
55                 Cur&=(~Operate[i][1]);
56                 q.push(make_pair(fi+Cost[i],Cur));
57             }
58         }
59     }
60 }
61 int main()
62 {
63     int i,j,t;
64     for(t=1;;t++)
65     {
66         Clean();
67         scanf("%d%d",&n,&m);
68         if(n==0&&m==0)
69             break;
70         for(i=1;i<=m;++i)
71         {
72             scanf("%d%s%s",&Cost[i],s1,s2);
73             for(j=0;j<n;++j)
74             {
75                 if(s1[j]==‘+‘)
76                     Condition[i][0]|=(1<<j);
77                 else if(s1[j]==‘-‘)
78                     Condition[i][1]|=(1<<j);
79             }
80             for(j=0;j<n;++j)
81             {
82                 if(s2[j]==‘+‘)
83                     Operate[i][0]|=(1<<j);
84                 else if(s2[j]==‘-‘)
85                     Operate[i][1]|=(1<<j);
86             }
87         }
88         Bfs();
89         printf("Product %d\n",t);
90         if(Sol)
91             printf("Fastest sequence takes %d seconds.\n\n",ans);
92         else
93             printf("Bugs cannot be fixed.\n\n");
94     }
95     return 0;
96 }