hdu 3065 病毒侵袭持续中 夜

http://acm.hdu.edu.cn/showproblem.php?pid=3065

AC自动机

代码：

#include<iostream>
#include<cmath>
#include<cstdio>
#include<string>
#include<cstring>
#include<vector>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<algorithm>

#define LL long long

using namespace std;

const int INF=0x3f3f3f3f;
const int N=1005;
const int M=505;
const int K=26;
struct nodeTrie
{
    nodeTrie()
    {
        v=0;
        fail=NULL;
        for(int i=0;i<K;++i)
        next[i]=NULL;
    }
    int v;
    nodeTrie *fail;
    nodeTrie *next[K];
}*root;
char s[N][55];
char web[2000005];
int num[N];
void addWord(nodeTrie *p,char *s,int k)
{
    if(s[0]=='\0') return ;
    for(int i=0;s[i]!='\0';++i)
    {
        if(p->next[s[i]-'A']==NULL)
        p->next[s[i]-'A']=new nodeTrie;
        p=p->next[s[i]-'A'];
    }
    (p->v)=k;
}
void init(int n)
{
    root=new nodeTrie;
    for(int i=1;i<=n;++i)
    {
        gets(s[i]);
        addWord(root,s[i],i);
    }
}
void bfs(nodeTrie *p)
{
    p->fail=root;
    queue<nodeTrie *>qt;
    qt.push(p);
    while(!qt.empty())
    {
        nodeTrie *y;
        nodeTrie *x=qt.front();qt.pop();
        for(int i=0;i<K;++i)
        if(x->next[i]!=NULL)
        {
            qt.push(x->next[i]);
            if(x==root)
            {x->next[i]->fail=root;continue;}
            y=x->fail;
            while(y!=root&&y->next[i]==NULL)
            y=y->fail;
            if(y->next[i]!=NULL)
            x->next[i]->fail=y->next[i];
            else
            x->next[i]->fail=root;
        }
    }
}
int match(nodeTrie *p,char *s)
{
    int wordCount=0;
    int l=0;
    while(s[l]!='\0')
    {
        if(s[l]<'A'||s[l]>'Z') {p=root;++l;continue;}
        while(p->next[s[l]-'A']==NULL&&p!=root)
        p=p->fail;
        if(p->next[s[l]-'A']!=NULL)
        p=p->next[s[l]-'A'];
        ++l;
        nodeTrie *fp=p;
        while(fp!=root)
        {
            if((fp->v)>0)
            ++num[fp->v];
            fp=fp->fail;
        }
    }
    return wordCount;
}
int main()
{
    //freopen("data.in","r",stdin);
    int n;
    while(scanf("%d ",&n)!=EOF)
    {
        init(n);
        bfs(root);
        gets(web);
        memset(num,0,sizeof(num));
        match(root,web);
        for(int i=1;i<=n;++i)
        if(num[i]>0)
        printf("%s: %d\n",s[i],num[i]);
    }
    return 0;
}