hdu 1686 Oulipo -- （KMP模板题）

Oulipo

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 9814    Accepted Submission(s): 3910

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

 

#include <stdio.h>#include <string.h>#define N 1000005char t[N],w[N];     //t是主串int next[N];void get_next(char *a,int len){next[0]=-1;int i=0,j=-1;while(i<len){if(j==-1||a[i]==a[j]){if(a[++i]==a[++j]) next[i]=next[j];else next[i]=j;}else j=next[j];}}int KMP(char *a,char *b){  //a是主串int i=0,j=0;int sum=0;int lena=strlen(a);int lenb=strlen(b);get_next(b,lenb);while(i<lena&&j<lenb){if(j==-1||a[i]==b[j]) i++,j++;else  j=next[j];if(j==lenb){sum++;j=next[j];  //可以重叠//j=0 不可以重叠}}return sum;}int main(){int n;scanf("%d",&n);while(n--){scanf("%s%s",&w,&t);printf("%d\n",KMP(t,w));}return 0;}