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

 

#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;
int  b[10005];//之前用next[10005]CE，不明确，可能有函数吧。。。，好坑
char ch1[1000005],ch2[1000005];
void get_next(int len1)
{
    int i=0,j=-1;
    b[0]=-1;
    while(i<len1)
    {
        if(j==-1||ch1[i]==ch1[j])
        {
            i++;j++;
            if(ch1[i]==ch1[j])
            b[i]=b[j];
            else
            b[i]=j;
        }
        else
        j=b[j];
    }
}
int  kmp(int len1,int len2)
{
    int i=0,j=0,k=0;
    get_next(len1);
    while(i<len2)
    {
        if(j==-1||ch2[i]==ch1[j])
        {i++;j++;}
        else
        {
           j=b[j];
        }
        if(j==len1)
        {
            k++;
        }
    }
    return k;
}

int main()
{
    int n;
    cin>>n;
    getchar();
    while(n--)
    {
        cin>>ch1>>ch2;
        int len1,len2;
        len1=strlen(ch1);
        len2=strlen(ch2);
        get_next(len1);
        cout<<kmp(len1,len2)<<endl;
    }
    return 0;
}