AC自动机 专题

  1 // 求目标串中出现了几个模式串
  2 //====================
  3 #include <stdio.h>
  4 #include <algorithm>
  5 #include <iostream>
  6 #include <string.h>
  7 #include <queue>
  8 using namespace std;
  9 
 10 struct Trie
 11 {
 12     int next[500010][26],fail[500010],end[500010];
 13     int root,L;
 14     int newnode()
 15     {
 16         for(int i = 0;i < 26;i++)
 17             next[L][i] = -1;
 18         end[L++] = 0;
 19         return L-1;
 20     }
 21     void init()
 22     {
 23         L = 0;
 24         root = newnode();
 25     }
 26     void insert(char buf[])
 27     {
 28         int len = strlen(buf);
 29         int now = root;
 30         for(int i = 0;i < len;i++)
 31         {
 32             if(next[now][buf[i]-‘a‘] == -1)
 33                 next[now][buf[i]-‘a‘] = newnode();
 34             now = next[now][buf[i]-‘a‘];
 35         }
 36         end[now]++;
 37     }
 38     void build()
 39     {
 40         queue<int>Q;
 41         fail[root] = root;
 42         for(int i = 0;i < 26;i++)
 43             if(next[root][i] == -1)
 44                 next[root][i] = root;
 45             else
 46             {
 47                 fail[next[root][i]] = root;
 48                 Q.push(next[root][i]);
 49             }
 50         while( !Q.empty() )
 51         {
 52             int now = Q.front();
 53             Q.pop();
 54             for(int i = 0;i < 26;i++)
 55                 if(next[now][i] == -1)
 56                     next[now][i] = next[fail[now]][i];
 57                 else
 58                 {
 59                     fail[next[now][i]]=next[fail[now]][i];
 60                     Q.push(next[now][i]);
 61                 }
 62         }
 63     }
 64     int query(char buf[])
 65     {
 66         int len = strlen(buf);
 67         int now = root;
 68         int res = 0;
 69         for(int i = 0;i < len;i++)
 70         {
 71             now = next[now][buf[i]-‘a‘];
 72             int temp = now;
 73             while( temp != root )
 74             {
 75                 res += end[temp];
 76                 end[temp] = 0;
 77                 temp = fail[temp];
 78             }
 79         }
 80         return res;
 81     }
 82     void debug()
 83     {
 84         for(int i = 0;i < L;i++)
 85         {
 86             printf("id = %3d,fail = %3d,end = %3d,chi = [",i,fail[i],end[i]);
 87             for(int j = 0;j < 26;j++)
 88                 printf("%2d",next[i][j]);
 89             printf("]\n");
 90         }
 91     }
 92 };
 93 char buf[1000010];
 94 Trie ac;
 95 int main()
 96 {
 97     int T;
 98     int n;
 99     scanf("%d",&T);
100     while( T-- )
101     {
102         scanf("%d",&n);
103         ac.init();
104         for(int i = 0;i < n;i++)
105         {
106             scanf("%s",buf);
107             ac.insert(buf);
108         }
109         ac.build();
110         scanf("%s",buf);
111         printf("%d\n",ac.query(buf));
112     }
113     return 0;
114 }

//输出每个模式串出现的次数


#include <iostream>
#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <queue>
using namespace std;

char str[1010][100];
struct Trie
{
    int next[1010*50][128],fail[1010*50],end[1010*50];
    int root,L;
    int newnode()
    {
        for(int i = 0;i < 128;i++)
            next[L][i] = -1;
        end[L++] = -1;
        return L-1;
    }
    void init()
    {
        L = 0;
        root = newnode();
    }
    void insert(char s[],int id)
    {
        int len = strlen(s);
        int now = root;
        for(int i = 0;i < len;i++)
        {
            if(next[now][s[i]] == -1)
                next[now][s[i]] = newnode();
            now = next[now][s[i]];
        }
        end[now] = id;
    }
    void build()
    {
        queue<int>Q;
        fail[root] = root;
        for(int i = 0;i < 128;i++)
            if(next[root][i] == -1)
                next[root][i] = root;
            else
            {
                fail[next[root][i]] = root;
                Q.push(next[root][i]);
            }
        while(!Q.empty())
        {
            int now = Q.front();
            Q.pop();
            for(int i = 0;i < 128;i++)
                if(next[now][i] == -1)
                    next[now][i]=next[fail[now]][i];
                else
                {
                    fail[next[now][i]]=next[fail[now]][i];
                    Q.push(next[now][i]);
                }
        }
    }
    int num[1010];
    void query(char buf[],int n)
    {
        for(int i = 0;i < n;i++)
            num[i] = 0;
        int len=strlen(buf);
        int now=root;
        for(int i=0;i<len;i++)
        {
            now=next[now][buf[i]];
            int temp = now;
            while( temp != root )
            {
                if(end[temp] != -1)
                    num[end[temp]]++;
                temp = fail[temp];
            }
        }
        for(int i = 0;i < n;i++)
            if(num[i] > 0)
                printf("%s: %d\n",str[i],num[i]);
    }

};

char buf[2000010];
Trie ac;
void debug()
{
    for (int i = 0; i < ac.L; i++)
    {
        printf("id = %3d ,fail = %3d ,end = %3d, chi = [",i,ac.fail[i],ac.end[i]);
        for (int j = 0; j < 128; j++)
            printf("%2d ",ac.next[i][j]);
        printf("]\n");
    }
}
int main()
{
//    freopen("in.txt","r",stdin);
//    freopen("out.txt","w",stdout);
    int n;
    while(scanf("%d",&n) == 1)
    {
        ac.init();
        for(int i = 0;i < n;i++)
        {
            scanf("%s",str[i]);
            ac.insert(str[i],i);
        }
        ac.build();
        scanf("%s",buf);
        ac.query(buf,n);
    }
    return 0;
}