hdu 1686Oulipo

http://acm.hdu.edu.cn/showproblem.php?pid=1686

Oulipo

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 2553    Accepted Submission(s): 986

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

#include<stdio.h>
#include<string.h>
char F[10010010];
char S[10010];
int next[10010];
int lenF;
int lenS;
void get_next()
{
    int i=1;
    int j=0;
    next[1]=0;
    while(i<=lenS)//漏了等号错好几次，不是很理解 
    {
        if(j==0||S[i]==S[j])
        {
            i++;
            j++;
            if(S[i]!=S[j])
            next[i]=j;
            else next[i]=next[j];
        }
        else
        {
           j=next[j];
         }
         //printf("%d\n",j);
    }
}

void kmp()
{
    int i=1;
    int j=1;
    int count=0;
    while(i<=lenF&&j<=lenS)
    {
        if(j==0||F[i]==S[j])
        {
            i++;
            j++;
        }
        else 
        {
            j=next[j];
        }
        if(j>lenS)
        {
            count++;
            j=next[j];
        }
    }
    printf("%d\n",count);
}
int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%s",S+1);
        scanf("%s",F+1);
        lenS=strlen(S+1);
        lenF=strlen(F+1);
        get_next();
        kmp();
    }
}