裸的KMP,但是用AC自動機做的。。。。
Oulipo
Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 4076 Accepted Submission(s): 1618
Problem Description
The French author Georges Perec (1936–1982) once wrote a book, La disparition, without the letter 'e'. He was a member of the Oulipo group. A quote from the book:
Tout avait Pair normal, mais tout s’affirmait faux. Tout avait Fair normal, d’abord, puis surgissait l’inhumain, l’affolant. Il aurait voulu savoir où s’articulait l’association qui l’unissait au roman : stir son tapis, assaillant à tout instant son imagination,
l’intuition d’un tabou, la vision d’un mal obscur, d’un quoi vacant, d’un non-dit : la vision, l’avision d’un oubli commandant tout, où s’abolissait la raison : tout avait l’air normal mais…
Perec would probably have scored high (or rather, low) in the following contest. People are asked to write a perhaps even meaningful text on some subject with as few occurrences of a given “word” as possible. Our task is to provide the jury with a program that
counts these occurrences, in order to obtain a ranking of the competitors. These competitors often write very long texts with nonsense meaning; a sequence of 500,000 consecutive 'T's is not unusual. And they never use spaces.
So we want to quickly find out how often a word, i.e., a given string, occurs in a text. More formally: given the alphabet {'A', 'B', 'C', …, 'Z'} and two finite strings over that alphabet, a word W and a text T, count the number of occurrences of W in T. All
the consecutive characters of W must exactly match consecutive characters of T. Occurrences may overlap.
Input
The first line of the input file contains a single number: the number of test cases to follow. Each test case has the following format:
One line with the word W, a string over {'A', 'B', 'C', …, 'Z'}, with 1 ≤ |W| ≤ 10,000 (here |W| denotes the length of the string W).
One line with the text T, a string over {'A', 'B', 'C', …, 'Z'}, with |W| ≤ |T| ≤ 1,000,000.
Output
For every test case in the input file, the output should contain a single number, on a single line: the number of occurrences of the word W in the text T.
Sample Input
3
BAPC
BAPC
AZA
AZAZAZA
VERDI
AVERDXIVYERDIAN
Sample Output
1
3
0
Source
華東區大學生程序設計邀請賽_熱身賽
#include
#include
#include
#include
#include
using namespace std;
const int maxn=11000;
char str[1100000];
int ch[maxn][26],fail[maxn],end[maxn];
int Size,root;
int dp[maxn];
int idx(char x) { return x-'A'; }
int newnode()
{
memset(ch[Size],-1,sizeof(ch[Size]));
end[Size++]=0;
return Size-1;
}
void ac_init()
{
Size=0; root=newnode();
}
void ac_insert(char str[])
{
int len=strlen(str);
int now=root;
for(int i=0;i q;
fail[root]=root;
for(int i=0;i<26;i++)
{
if(ch[root][i]==-1)
ch[root][i]=root;
else
{
fail[ch[root][i]]=root;
q.push(ch[root][i]);
}
}
while(!q.empty())
{
int now=q.front(); q.pop();
for(int i=0;i<26;i++)
{
if(ch[now][i]==-1)
ch[now][i]=ch[fail[now]][i];
else
{
fail[ch[now][i]]=ch[fail[now]][i];
q.push(ch[now][i]);
}
}
}
}
int ac_query(char str[])
{
int len=strlen(str);
int now=root;
int ret=0;
memset(dp,-1,sizeof(dp));
for(int i=0;i