POJ 3461 Oulipo

Oulipo
Time Limit: 1000MS Memory Limit: 65536K
Total Submissions: 42555 Accepted: 17085
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

//裸的KMP#include<iostream>#include<cstring>#include<cstdio>#include<cstdlib>using namespace std;#define MAXN 100010char s[MAXN*10],p[MAXN];int next[MAXN],n;void Get_Next(int lenp){    int i=0,j=-1;next[i]=j;    while(i!=lenp){        if(j==-1||s[i]==s[j])            next[++i] = ++j;        else j=next[j];    }}int Kmp(int lens,int lenp){    int i=0,j=0,count=0;    while(i!=lens&&j!=lenp){        if(s[i]==p[j]||j==-1)            ++i,++j;        else j=next[j];        if(j==lenp) ++count,j=next[j];    }    return count;}int main(){    scanf("%d",&n);    while(n--){        scanf("%s%s",p,s);        int lens=strlen(s),lenp=strlen(p);        Get_Next(lenp);        int ans=Kmp(lens,lenp);        printf("%d\n",ans);    }    return 0;}