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Fitz

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Resource Archiver HDU - 3247 AC自动机+BFS+状压

题意:

给出n个资源串,m个病毒串,现在要如何连接资源串使得不含病毒串(可以重叠,样例就是重叠的)。

 

题解:

这题的套路和之前的很不同了,之前的AC自动机+DP的题目一般都是通过teir图去转移,

这题有点小不同,认真分析这一题,我们可以知道n个资源串,m个病毒串在AC自动机的上面是哪一个节点

所以可以根据teir图去处理出每一个资源串的节点不经过病毒串节点的最短距离,这个可以通过BFS实现。

这个一开始要处理AC自动机上的root节点,毕竟是从root节点开始走的。

处理出了每个点到其他点的最短距离之后,就变成了一个TSP问题,必须经过几个点的最短距离,状压写即可。

  1 #include <set>
  2 #include <map>
  3 #include <stack>
  4 #include <queue>
  5 #include <cmath>
  6 #include <ctime>
  7 #include <cstdio>
  8 #include <string>
  9 #include <vector>
 10 #include <cstring>
 11 #include <iostream>
 12 #include <algorithm>
 13 #include <unordered_map>
 14 
 15 #define  pi    acos(-1.0)
 16 #define  eps   1e-9
 17 #define  fi    first
 18 #define  se    second
 19 #define  rtl   rt<<1
 20 #define  rtr   rt<<1|1
 21 #define  bug                printf("******\n")
 22 #define  mem(a, b)          memset(a,b,sizeof(a))
 23 #define  name2str(x)        #x
 24 #define  fuck(x)            cout<<#x" = "<<x<<endl
 25 #define  sfi(a)             scanf("%d", &a)
 26 #define  sffi(a, b)         scanf("%d %d", &a, &b)
 27 #define  sfffi(a, b, c)     scanf("%d %d %d", &a, &b, &c)
 28 #define  sffffi(a, b, c, d) scanf("%d %d %d %d", &a, &b, &c, &d)
 29 #define  sfL(a)             scanf("%lld", &a)
 30 #define  sffL(a, b)         scanf("%lld %lld", &a, &b)
 31 #define  sfffL(a, b, c)     scanf("%lld %lld %lld", &a, &b, &c)
 32 #define  sffffL(a, b, c, d) scanf("%lld %lld %lld %lld", &a, &b, &c, &d)
 33 #define  sfs(a)             scanf("%s", a)
 34 #define  sffs(a, b)         scanf("%s %s", a, b)
 35 #define  sfffs(a, b, c)     scanf("%s %s %s", a, b, c)
 36 #define  sffffs(a, b, c, d) scanf("%s %s %s %s", a, b,c, d)
 37 #define  FIN                freopen("../in.txt","r",stdin)
 38 #define  gcd(a, b)          __gcd(a,b)
 39 #define  lowbit(x)          x&-x
 40 #define  IO                 iOS::sync_with_stdio(false)
 41 
 42 
 43 using namespace std;
 44 typedef long long LL;
 45 typedef unsigned long long ULL;
 46 const ULL seed = 13331;
 47 const LL INFLL = 0x3f3f3f3f3f3f3f3fLL;
 48 const int maxn = 1e6 + 7;
 49 const int maxm = 8e6 + 10;
 50 const int INF = 0x3f3f3f3f;
 51 const int mod = 1e9 + 7;
 52 int n, m;
 53 char buf[maxn];
 54 
 55 struct Aho_Corasick {
 56     int next[60010][2], fail[60010], End[60010];
 57     int root, cnt;
 58 
 59     int newnode() {
 60         for (int i = 0; i < 2; i++) next[cnt][i] = -1;
 61         End[cnt++] = 0;
 62         return cnt - 1;
 63     }
 64 
 65     void init() {
 66         cnt = 0;
 67         root = newnode();
 68     }
 69 
 70     void insert(char buf[], int id) {
 71         int len = strlen(buf);
 72         int now = root;
 73         for (int i = 0; i < len; i++) {
 74             if (next[now][buf[i] - '0'] == -1) next[now][buf[i] - '0'] = newnode();
 75             now = next[now][buf[i] - '0'];
 76         }
 77         End[now] = id;
 78     }
 79 
 80     void build() {
 81         queue<int> Q;
 82         fail[root] = root;
 83         for (int i = 0; i < 2; i++)
 84             if (next[root][i] == -1) next[root][i] = root;
 85             else {
 86                 fail[next[root][i]] = root;
 87                 Q.push(next[root][i]);
 88             }
 89         while (!Q.empty()) {
 90             int now = Q.front();
 91             Q.pop();
 92             if (End[fail[now]] == -1) End[now] = -1;
 93             else End[now] |= End[fail[now]];
 94             for (int i = 0; i < 2; i++)
 95                 if (next[now][i] == -1) next[now][i] = next[fail[now]][i];
 96                 else {
 97                     fail[next[now][i]] = next[fail[now]][i];
 98                     Q.push(next[now][i]);
 99                 }
100         }
101     }
102 
103     int mp[15][15], dis[60010], pos[15], num, dp[15][1055];
104 
105     void bfs(int x) {
106         mem(dis, -1);
107         dis[pos[x]] = 0;
108         queue<int> q;
109         q.push(pos[x]);
110         while (!q.empty()) {
111             int now = q.front();
112             q.pop();
113             for (int i = 0; i < 2; ++i) {
114                 int idx = next[now][i];
115                 if (End[idx] == -1 || dis[idx] >= 0) continue;
116                 dis[idx] = dis[now] + 1, q.push(idx);
117             }
118         }
119         for (int i = 0; i < num; ++i) mp[x][i] = dis[pos[i]];
120     }
121 
122     int solve() {
123         pos[0] = 0, num = 1;
124         for (int i = 0; i < cnt; ++i) if (End[i] > 0) pos[num++] = i;
125         for (int i = 0; i < num; ++i) bfs(i);
126 
127 //        for (int i = 0; i < num; ++i) {
128 //            for (int j = 0; j < num; ++j) {
129 //                printf("%d ", mp[i][j]);
130 //            }
131 //            printf("\n");
132 //        }
133 
134 
135         for (int i = 0; i < num; ++i)
136             for (int j = 0; j < (1 << n); ++j)
137                 dp[i][j] = INF;
138         dp[0][0] = 0;
139         for (int status = 0; status < (1 << n); ++status) {
140             for (int i = 0; i < num; ++i) {
141                 if (dp[i][status] == INF) continue;
142                 for (int j = 0; j < num; ++j) {
143                     if (mp[i][j] == -1 || (status | End[pos[j]]) == status) continue;
144                     dp[j][status | End[pos[j]]] = min(dp[j][status | End[pos[j]]], dp[i][status] + mp[i][j]);
145                 }
146             }
147         }
148         int ans = INF;
149         for (int i = 0; i < num; ++i) ans = min(ans, dp[i][(1 << n) - 1]);
150         return ans;
151     }
152 
153     void debug() {
154         for (int i = 0; i < cnt; i++) {
155             printf("id = %3d,fail = %3d,end = %3d,chi = [", i, fail[i], End[i]);
156             for (int j = 0; j < 26; j++) printf("%2d", next[i][j]);
157             printf("]\n");
158         }
159     }
160 } ac;
161 
162 int main() {
163    // FIN;
164     while (~sffi(n, m)) {
165         if (n == 0 && m == 0) break;
166         ac.init();
167         for (int i = 0; i < n; ++i) {
168             sfs(buf);
169             ac.insert(buf, (1 << i));
170         }
171         for (int i = 0; i < m; ++i) {
172             sfs(buf);
173             ac.insert(buf, -1);
174         }
175         ac.build();
176         printf("%d\n", ac.solve());
177     }
178     return 0;
179 }
View Code

 

posted @ 2019-08-19 20:47  Fitz~  阅读(229)  评论(0编辑  收藏  举报