Oulipo

Time Limit: 1000MS

 

Memory Limit: 65536K

Total Submissions: 45515

 

Accepted: 18181

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.

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.

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.

3
BAPC
BAPC
AZA
AZAZAZA
VERDI
AVERDXIVYERDIAN

1
3
0

#include
#include
#include
#include
using namespace std;
int n,k,len1,len2;
int next1[];
char s1[];
char s2[];
long long HASH[];
long long E[],M=;

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