【HDOJ】4057 Rescue the Rabbit

挺有意思的一道题目，解法是AC自动机+DP。
AC自动机建立fail指针时，一定要注意结点的属性也需要传递。AC自动机结合了trie和kmp的优点。
需要注意的是，每个模式串仅计算一次，否则这题很难解。

 /* 4057 */
 #include <iostream>
 #include <sstream>
 #include <string>
 #include <map>
 #include <queue>
 #include <set>
 #include <stack>
 #include <vector>
 #include <deque>
 #include <algorithm>
 #include <cstdio>
 #include <cmath>
 #include <ctime>
 #include <cstring>
 #include <climits>
 #include <cctype>
 #include <cassert>
 #include <functional>
 #include <iterator>
 #include <iomanip>
 using namespace std;
 //#pragma comment(linker,"/STACK:102400000,1024000")

 #define sti                set<int>
 #define stpii            set<pair<int, int> >
 #define mpii            map<int,int>
 #define vi                vector<int>
 #define pii                pair<int,int>
 #define vpii            vector<pair<int,int> >
 #define rep(i, a, n)     for (int i=a;i<n;++i)
 #define per(i, a, n)     for (int i=n-1;i>=a;--i)
 #define clr                clear
 #define pb                 push_back
 #define mp                 make_pair
 #define fir                first
 #define sec                second
 #define all(x)             (x).begin(),(x).end()
 #define SZ(x)             ((int)(x).size())
 #define lson            l, mid, rt<<1
 #define rson            mid+1, r, rt<<1|1

 const int maxn = ;
 const int maxm = ;
 const int maxl = ;
 char s[maxl];
 int W[maxn];
 bool dp[][maxm][maxm];
 int n, m, l;

 typedef struct {
     static const int maxn = ;
     static const int rt = ;
     int nxt[maxn][];
     int fail[maxn];
     int f[maxn];
     int m;

     void init() {
         m = ;
         memset(f, , sizeof(f));
         memset(nxt, , sizeof(nxt));
     }

     int newNode() {
         return ++m;
     }    

     int getId(char c) {
         if (c == 'A')    return ;
         if (c == 'T')    return ;
         if (c == 'G')    return ;
         if (c == 'C')    return ;
         return -;
     }

     void Insert(char *s, int k) {
         int i = , id;
         int p = , q;

         while (s[i]) {
             id = getId(s[i]);
             q = nxt[p][id];
             if (!q)
                 q = nxt[p][id] = newNode();
             p = q;
             ++i;
         }
         f[p] |= ( << k);
     }

     void Build() {
         int cur;
         queue<int> Q;

         fail[rt] = rt;
         rep(i, , ) {
             if (nxt[rt][i] == ) {
                 nxt[rt][i] = rt;
             } else {
                 fail[nxt[rt][i]] = rt;
                 Q.push(nxt[rt][i]);
             }
         }

         while (!Q.empty()) {
             cur = Q.front();
             Q.pop();
             rep(i, , ) {
                 if (nxt[cur][i] == ) {
                     nxt[cur][i] = nxt[fail[cur]][i];
                 } else {
                     fail[nxt[cur][i]] = nxt[fail[cur]][i];
                     f[nxt[cur][i]] |= f[nxt[fail[cur]][i]];
                     Q.push(nxt[cur][i]);
                 }
             }
         }
     }

 } AC;

 AC ac;

 int calw(int x) {
     int ret = ;

     rep(i, , n) {
         if (x & (<<i))
             ret += W[i];
     }

     return ret;
 }

 void solve() {
     int ans = INT_MIN;
     int mst = <<n, nst, nxt;
     int p = , q = ;

     m = ac.m;
     memset(dp, , sizeof(dp));
     dp[][ac.rt][] = true;
     rep(i, , l+) {
         memset(dp[q], , sizeof(dp[q]));
         rep(j, , m+) {
             rep(k, , ) {
                 rep(st, , mst) {
                     if (dp[p][j][st]) {
                         nxt = ac.nxt[j][k];
                         nst = st | ac.f[nxt];
                         dp[q][nxt][nst] = true;
                     }
                 }
             }
         }
         p = q;
         q ^= ;
     }

     rep(st, , mst) {
         rep(j, , m+) {
             if (dp[p][j][st]) {
                 ans = max(ans, calw(st));
                 break;
             }
         }
     }

     if (ans < )
         puts("No Rabbit after 2012!");
     else
         printf("%d\n", ans);
 }

 int main() {
     ios::sync_with_stdio(false);
     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
         freopen("data.out", "w", stdout);
     #endif

     int len, w;

     while (scanf("%d %d",&n,&l) != EOF) {
         ac.init();
         rep(i, , n) {
             scanf("%s %d", s, &W[i]);
             ac.Insert(s, i);
         }

         ac.Build();
         solve();
     }

     #ifndef ONLINE_JUDGE
         printf("time = %d.\n", (int)clock());
     #endif

     return ;
 }