Oulipo (kmp)

Oulipo

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 26857		Accepted: 10709

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

BAPC 2006 Qualification

#include<cstdio>
#include<cstring>
char t[10000 + 10] , s[1000000 + 10] ;
int nxt [10000 + 10] ;
int T ;
int lens , lent ;

void PMT ()
{
    nxt [0] = -1 ;
    for (int i = 1 , j = -1 ; i < lent ; i++) {
        while (j != -1 && t[i] != t[j + 1] ) {
            j = nxt[j] ;
        }
        nxt[i] = t[i] == t[j + 1] ? ++ j : j ;
    }
}

void kmp ()
{
    int ret = 0 ;
    PMT () ;//partial match table
    for (int i = 0 , j = - 1 ; i < lens ; i++) {
        while (j != - 1 && s[i] != t[j + 1] ) {
            j = nxt [j] ;
        }
        if (s[i] == t[j + 1]) {
            j ++ ;
            if (j == lent - 1) {
                j = nxt [j] ;
                ret ++ ;
            }
        }
    }
    printf ("%d
" , ret );
}

int main ()
{
   // freopen ("a.txt" , "r" , stdin ) ;
    scanf ("%d" , &T) ;
    getchar () ;
    while (T--) {
        memset (nxt , 0 , sizeof(nxt) ) ;
        gets (t) ;
        gets (s) ;
        lens = strlen (s) ;
        lent = strlen (t) ;
      //  puts (t) , puts (s) ;
        kmp () ;
    }
    return 0 ;
}