hdu 3065 病毒侵袭持续中 AC自动机

 AC自动机模板题，稍微改一改就可以了

AC自动机模板

这个题目坑在是多组样例输入

#include<bits/stdc++.h>
using namespace std;

const int maxn = 2000000+5;
const int nsize = 26;

struct node
{
    node *next[nsize];
    node *fail;
    int sum;
};

node *root;
int cnt[1005];

//构造字典树
void Insert(char *s, int id)
{
    node *newnode,*p;
    p = root;
    for(int i = 0; s[i]; i++)
    {
        int x = s[i] - 'A';
        if(p->next[x] == NULL)
        {
            newnode=(struct node *)malloc(sizeof(struct node));
            for(int j=0; j<nsize; j++) newnode->next[j] = 0;
            newnode->sum = 0;
            newnode->fail = 0;
            p->next[x]=newnode;
        }
        p = p->next[x];
    }
    p->sum = id;
}

//构造失败指针
void build_fail()
{
    queue<node*> Q;
    Q.push(root);
    while (!Q.empty())
    {
        node *p = Q.front();
        Q.pop();
        for(int i = 0; i < nsize; i++)
        {
            if (p->next[i])
            {
                if (p == root)
                    p->next[i]->fail = p;
                else
                {
                    node *tmp = p->fail;
                    while (tmp)
                    {
                        if (tmp->next[i])
                        {
                            p->next[i]->fail = tmp->next[i];
                            break;
                        }
                        else tmp = tmp->fail;
                    }
                    if (!tmp) p->next[i]->fail = root;
                }
                Q.push(p->next[i]);
            }
        }
    }
    return ;
}

//匹配
void ac_automation(char *ch)
{
    node *p = root;
    int len = strlen(ch);
    for(int i = 0; i < len; i++)
    {
        if(ch[i] > 'Z' || ch[i] < 'A')
        {
            p = root;
            continue;
        }
        int x = ch[i] - 'A';
        while(!p->next[x] && p != root)
        {
            p = p->fail;
            if(p->sum > 0)
            {
                cnt[p->sum]++;
            }
        }
        p = p->next[x];
        if(!p) p = root;
        node *temp = p;
        while(temp != root)
        {
            if(temp->sum > 0)
            {
                cnt[temp->sum]++;
            }
            else break;
            temp = temp->fail;
        }
    }
}

char sbs[1005][55],str[maxn];

int main()
{
//    freopen("in.txt","r",stdin);
    int N;
    root=(struct node *)malloc(sizeof(struct node));
    for(int j=0; j<nsize; j++) root->next[j] = 0;
    root->fail = 0;
    root->sum = 0;
    while(~scanf("%d",&N))
    {
        memset(cnt, 0, sizeof(cnt));
        for(int i = 1; i <= N; i++)
        {
            scanf("%s", sbs[i]);
            Insert(sbs[i], i);
        }
        build_fail();
        scanf("%s", str);
        ac_automation(str);
        for(int i = 1; i <= N; i++)
        {
            if(cnt[i] > 0)
                printf("%s: %d
", sbs[i], cnt[i]);
        }
    }
    return 0;
}