POJ

Oulipo

Time Limit: 1000MS Memory Limit: 65536KTotal Submissions: 43180 Accepted: 17372

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

3BAPCBAPCAZAAZAZAZAVERDIAVERDXIVYERDIAN

Sample Output

130

求子串出现次数

#include<iostream>#include<algorithm>#include<cstring>#include<cstdio>using namespace std;const int len=1e6+5;char a[len],b[len];int kmp_next[len];void KMP_next(){    int i=0,j=-1;    kmp_next[0]=-1;    while(a[i])        if(j==-1||a[i]==a[j])            kmp_next[++i]=++j;        else            j=kmp_next[j];}int KMP(){    KMP_next();    int i=0,j=0,ans=0,m=strlen(b);    while(a[i])    {        if(j==-1||a[i]==b[j])            ++i,++j;        else            j=kmp_next[j];        if(j==m)        {            ans++;            j=kmp_next[j];        }    }    return ans;}int main(){    int N;    cin>>N;    while(N--)    {        scanf("%s%s",b,a);        cout<<KMP()<<endl;    }    return 0;}