Oulipo【Hash】

　　

Oulipo

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 45515		Accepted: 18181

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

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
int n,k,len1,len2;
int next1[1000001];
char s1[1000001];
char s2[1000001];
long long HASH[1000001];
long long E[1000001],M=1234567898765;

long long EE = 97;
int init()
{
    long long Key=0;
    int ans=0;
    memset(E,0,sizeof(E));
    memset(HASH,0,sizeof(HASH));
    E[len2]=1;
    for (int i=len2-1;i>=1;i--)
        E[i]=E[i+1]*EE%M;
    for (int i=1;i<=len2;i++)
        HASH[1]=(HASH[1]+E[i]*(s1[i-1]))%M;
    for (int i=1;i<=len2;i++)
        Key=(Key+E[i]*(s2[i-1]))%M;
    if (HASH[1]==Key) ans++;
    for (int i=2;i<=len1-len2+1;i++)
    {
        HASH[i]=(HASH[i-1]-s1[i-2]*E[1]%M+M)%M*EE%M+s1[i-2+len2];
        if (HASH[i]==Key) ans++;
    }
    printf("%d
",ans);
}
int main(){ 
    int n;
    cin >> n;
    for (int i=1;i<=n;i++){
        scanf("%s",s2) ;
        scanf("%s",s1) ;
        len1=strlen(s1);
        len2=strlen(s2);
        init();
    }
    return 0;
}