hdu 3065 病毒侵袭持续中 (AC)

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

AC自动机，主要注意的就是两个特征码的重叠情况。

code:

#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std ;
const int kind = 30;
struct node{
node *fail ;
node *next[kind] ;
int count ;
int id ;
node(){
fail = NULL ;
count = 0 ;
id = -1 ;
memset(next, NULL, sizeof(next)) ;
}
}*q[500001] ;
char keyword[1001][51] ;
char str[2000001] ;
int head, tail, ID ;
int vis[1001] ;

void insert(char *str, node *root){
node *p = root ;
int i = 0, index ;
while(str[i]){
index = str[i] - 'A' ;
if(p->next[index]==NULL) p->next[index]=new node() ;
p = p->next[index] ;
i ++ ;
}
p->count ++ ;
p->id = ID ++ ;
}
void build_ac_automation(node *root){
int i ;
root->fail = NULL ;
q[head++] = root ;
while(head!=tail){
node *temp = q[tail++] ;
node *p = NULL ;
for(i=0; i<30; i++){
if(temp->next[i]!=NULL){
if(temp==root) temp->next[i]->fail = root ;
else{
p = temp->fail ;
while(p!=NULL){
if(p->next[i]!=NULL){
temp->next[i]->fail = p->next[i] ;
break ;
}
p = p->fail ;
}
if(p==NULL) temp->next[i]->fail = root ;
}
q[head++] = temp->next[i] ;
}
}
}
}
void query(node *root){
int i = 0, index ;
node *p = root ;
while(str[i]){
index = str[i] - 'A' ;
if(index<0||index>26)
index = 27 ;
while(p->next[index]==NULL && p!=root)
p = p->fail ;
p = p->next[index] ;
p = (p==NULL) ? root : p ;
node *temp = p ;
while(temp!=root){
if(temp->id!=-1)
vis[temp->id] ++ ;
temp = temp->fail ;
}
i ++ ;
}
}
int main(){
int n ;
while(~scanf("%d", &n)){
memset(vis, 0, sizeof(vis)) ;
head = tail = 0 ;
ID = 0 ;
node *root = new node() ;
for(int i=0; i<n; i++){
getchar() ;
scanf("%s", keyword[i]) ;
insert(keyword[i], root) ;
}
build_ac_automation(root) ;
getchar() ;
scanf("%s", str) ;
query(root) ;
for(int i=0; i<n; i++)
if(vis[i])
printf("%s: %d\n", keyword[i], vis[i]) ;
}
return 0 ;}