HDU 1686 Oulipo(KMP)

Oulipo

Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 8826 Accepted Submission(s): 3565

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

3BAPCBAPCAZAAZAZAZAVERDIAVERDXIVYERDIAN

Sample Output

130

Source

华东区大学生程序设计邀请赛_热身赛  

#include <iostream>#include <cstdio>#include <string.h>using namespace std;const int N=10000+10;char text[N*100];char pat[N];int tlen,plen;int nextKmp[N];inline void getNext(){int j=0,k=-1;nextKmp[0]=-1;while(j<plen){if(k==-1||text[j]==pat[k])  nextKmp[++j]=++k;else  k=nextKmp[k];}}inline int find(){    int i=0,j=0,re=0;     while(i<tlen){if(j==-1||text[i]==pat[j]){i++;j++;}else   j=nextKmp[j];if(j==plen) re++;}return re;}int main(){     int n,re;    scanf("%d",&n);    while(n--){    scanf("%s",pat);scanf("%s",text);    plen=strlen(pat);    tlen=strlen(text);    getNext();    re=find();        printf("%d\n",re);}return 0;}