POJ-3461 Oulipo

Oulipo

Time Limit: 1000MS Memory Limit: 65536KTotal Submissions: 39193 Accepted: 15783

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

简单KMP

#include <iostream>#include <stdio.h>#include <string.h>using namespace std;#define N 10010char t[N*100];char p[N];int f[N];void GetFail(char* p,int* f){    int m=strlen(p);    f[0]=0;f[1]=0;    for(int i=1;i<m;i++)    {        int j=f[i];        while(j&&p[i]!=p[j])            j=f[j];        f[i+1]=p[i]==p[j]?j+1:0;    }}int find (char* t,char* p,int* f){    int ans=0;    int n=strlen(t);    int m=strlen(p);    GetFail(p,f);    int j=0;    for(int i=0;i<n;i++)    {        while(j&&p[j]!=t[i])            j=f[j];        if(p[j]==t[i])            j++;        if(j==m)            //printf("%d\n",i-m+1);        {            ans++;        }    }    return ans;}int main(){    int T;    scanf("%d",&T);    while(T--)    {        scanf("%s%s",p,t);        int res=find(t,p,f);        printf("%d\n",res);    }    return 0;}