POJ3461 Oulipo

 

Oulipo

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 36441		Accepted: 14728

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

 

问字符串2中包含多少个字符串1。

KMP匹配即可

/**/
#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
using namespace std;
const int mxn=1000020;
char s[mxn];
char a[10020];
int next[mxn];
int f[mxn];
int lens,lena;
void gne(){
    next[0]=-1;
    int i,j=-1;
    for(i=1;i<lena;i++){
        while(j>=0 && a[j+1]!=a[i])j=next[j];
        if(a[j+1]==a[i])j++;
        next[i]=j;
    }
    return;
}
int main(){
    int T;
    scanf("%d",&T);
    int i,j;
    while(T--){
        scanf("%s%s",a,s);
        lena=strlen(a);
        lens=strlen(s);
        gne();
        j=-1;
        int ans=0,last=0;
        for(i=0;i<lens;i++){
            while(j>=0 && a[j+1]!=s[i])j=next[j];
            if(a[j+1]==s[i])j++;
            f[i]=j;
            if(f[i]==lena-1){
                ans++;
                j=next[j];
            }
        }
        printf("%d\n",ans);
    }
    return 0;
}