hdu1686Oulipo(kmp模版)

Oulipo

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 3770    Accepted Submission(s): 1485

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>
using namespace std;
const int MAXN = 1000005;
const int MAXM = 10005;
char text[MAXN];
char pattern[MAXM];
int next[MAXM];
int n,m,t;

void get_next(){
    next[0]=next[1]=0;
    for(int i=1; i<m; i++){
        int j=next[i];
        while(j && pattern[i]!=pattern[j]) j=next[j];
        next[i+1]=(pattern[i]==pattern[j]? j+1 : 0);
    }
}

//void get_next(){
//    int i=0, j=-1;
//    next[i]=j;
//    while(i<m){
//        if(j==-1 || pattern[i]==pattern[j]){
//            j++; i++;
//            next[i]=j;
//        }else
//            j=next[j];
//    }
//}

void kmp(){
    int cnt=0,j=0;
    for(int i=0; i<n; i++){
        while(j && text[i]!=pattern[j]) j=next[j];
        if(text[i]==pattern[j]) j++;
        if(j==m){
            cnt++;
        }
    }
    cout<<cnt<<endl;
}

int main()
{
    cin>>t;
    while(t--){
        cin>>pattern>>text;
        m = strlen(pattern);
        n = strlen(text);
        get_next();
        kmp();
    }
    return 0;
}