HDU 3341 Lost's revenge

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 const int maxn = 510;
 4 struct Trie {
 5     int ch[maxn][4],fail[maxn],cnt[maxn],tot;
 6     int id[256];
 7     void init() {
 8         tot = 0;
 9         newnode();
10         for(int i = 0; i < 4; ++i) id["ACGT"[i]] = i;
11     }
12     int newnode() {
13         memset(ch[tot],0,sizeof ch[tot]);
14         fail[tot] = cnt[tot] = 0;
15         return tot++;
16     }
17     void insert(char *str,int rt = 0) {
18         for(int i = 0; str[i]; ++i) {
19             int &x = ch[rt][id[str[i]]];
20             if(!x) x = newnode();
21             rt = x;
22         }
23         cnt[rt]++;
24     }
25     void build(int rt = 0) {
26         queue<int>q;
27         for(int i = 0; i < 4; ++i)
28             if(ch[rt][i]) q.push(ch[rt][i]);
29         while(!q.empty()) {
30             rt = q.front();
31             q.pop();
32             cnt[rt] += cnt[fail[rt]];
33             for(int i = 0; i < 4; ++i) {
34                 int &x = ch[rt][i],y = ch[fail[rt]][i];
35                 if(x) {
36                     fail[x] = y;
37                     q.push(x);
38                 } else x = y;
39             }
40         }
41     }
42     int dp[maxn][11*11*11*11 + 5];
43     int solve(char *str) {
44         int bt[4] = {0,0,0,1},num[4] = {};
45         for(int i = 0; str[i]; ++i) ++num[id[str[i]]];
46         for(int i = 2; i >= 0; --i)
47             bt[i] = bt[i + 1]*(num[i] + 1);
48         memset(dp,-1,sizeof dp);
49         int ans = dp[0][0] = 0;
50         for(int a = 0; a <= num[0]; ++a)
51             for(int b = 0; b <= num[1]; ++b)
52                 for(int c = 0; c <= num[2]; ++c)
53                     for(int d = 0; d <= num[3]; ++d) {
54                         int hs = a*bt[0] + b*bt[1] + c*bt[2] + d;
55                         for(int i = 0; i < tot; ++i) {
56                             if(dp[i][hs] == -1) continue;
57                             for(int k = 0; k < 4; ++k) {
58                                 if(a == num[0] && k == 0) continue;
59                                 if(b == num[1] && k == 1) continue;
60                                 if(c == num[2] && k == 2) continue;
61                                 if(d == num[3] && k == 3) continue;
62                                 int x = dp[ch[i][k]][hs + bt[k]];
63                                 int y = dp[i][hs] + cnt[ch[i][k]];
64                                 dp[ch[i][k]][hs + bt[k]] = max(x,y);
65                             }
66                         }
67                     }
68         int st = num[0]*bt[0] + num[1]*bt[1] + num[2]*bt[2] + num[3]*bt[3];
69         for(int i = 0; i < tot; ++i)
70             ans = max(ans,dp[i][st]);
71         return ans;
72     }
73 } ac;
74 char str[maxn];
75 int main() {
76     int n,cs = 1;
77     while(scanf("%d",&n),n){
78         ac.init();
79         while(n--){
80             scanf("%s",str);
81             ac.insert(str);
82         }
83         scanf("%s",str);
84         ac.build();
85         printf("Case %d: %d\n",cs++,ac.solve(str));
86     }
87     return 0;
88 }