HDU 3065 病毒侵袭持续中(AC自动机)

题目：戳这里

题意：输出主串中出现的模式串以及该模式串出现的次数。

思路：ac自动机，匹配的时候对应的vis[]+1即可

代码：

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<queue>
using namespace std;
const int maxw = 26;
const int maxn = 55;
const int time = 1010;
const int maxs = 2000005;
struct Tire
{
    int tire[maxn*time][maxw];
    int fail[maxn*time];
    int tag[maxn*time];
    int vis[time];
    int P, root;
    int New()
    {
        for(int i=0; i<maxw; i++) tire[P][i]=-1;
        tag[P]=0;
        return P++;
    }
    void init()
    {
        P=0;
        root =New();
    }
    void Insert(char ch[], int id)
    {
        int now = root;
        for(int i=0; ch[i]; i++)
        {
            if(tire[now][ch[i]-'A']==-1) tire[now][ch[i]-'A'] = New();
            now = tire[now][ch[i]-'A'];
        }
        tag[now] = id;
    }
    void build()
    {
        queue<int>Q;
        for(int i=0; i<maxw; i++)
        {
            if(tire[root][i]!=-1)
            {
                fail[tire[root][i]] = root;
                Q.push(tire[root][i]);
            }
            else tire[root][i] = root;
        }
        while(!Q.empty())
        {
            int now = Q.front();
            Q.pop();
            for(int i=0; i<maxw; i++)
            {
                if(tire[now][i]!=-1)
                {
                    fail[tire[now][i]] = tire[fail[now]][i];
                    Q.push(tire[now][i]);
                }
                else tire[now][i] = tire[fail[now]][i];
            }
        }
    }
    void match(char ch[])
    {
        int now = root;
        memset(vis,0,sizeof(vis));
        for(int i=0; ch[i]; i++)
        {
            if(ch[i]<'A'||ch[i]>'Z') now = root;
            else
            {
                now = tire[now][ch[i]-'A'];
                int tmp = now;
                while(tmp!=0)
                {
                    if(tag[tmp]) vis[tag[tmp]]++;
                    tmp = fail[tmp];
                }
            }
        }
    }
};
char ch[time][maxn], def[maxs];
int n;
Tire ac;
int main()
{
    while(~scanf("%d",&n))
    {
        ac.init();
        for(int i=1; i<=n; i++)
        {
            scanf("%s",ch[i]);
            ac.Insert(ch[i],i);
        }
        ac.build();
        scanf("%s",def);
        ac.match(def);
        for(int i=1; i<=n; i++)
        {
            if(ac.vis[i]!=0)
                printf("%s: %d
",ch[i],ac.vis[i]);
        }
    }
}