hdu1686 Oulipo

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

华东区大学生程序设计邀请赛_热身赛

同样KMP模板题，不过这次是对付字符串~

#include <stdio.h>
#include <string.h>

int n,m;
char a[1000005];
char b[10005];
int p[10005];

void Pre()
{
    int i,j;
    j=-1;
    p[0]=-1;
    for (i=1;i<m;i++)
    {
        while(j>=0 && b[j+1]!=b[i]) j=p[j];
        if (b[j+1]==b[i]) j++;
        p[i]=j;
    }
}

int Solve()
{
    int i,j,cnt;
    cnt=0;
    j=-1;
    for (i=0;i<n;i++)
    {
        while(j>=0 && b[j+1]!=a[i]) j=p[j];
        if (b[j+1]==a[i]) j++;
        if (j==m-1) cnt++;
    }
    return cnt;
}

int main()
{
    int i,j,T;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%s",b);
        scanf("%s",a);
        n=strlen(a);
        m=strlen(b);
        Pre();
        printf("%d\n",Solve());
    }
    return 0;
}