Oulipo poj+KMP水题

Oulipo

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 22728		Accepted: 9084

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

解决方案：KMP水题，没什么好说的啦。
code：

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int small=10003;
const int big=1000003;
char text[big];
char word[small];
int next[small];
void getnext(int len){

int i=0,j=-1;
next[0]=-1;
while(i<len){
if(j==-1||word[i]==word[j]){
j++;
i++;
next[i]=j;
}
else j=next[j];
}

}
int main()
{
int t;
scanf("%d",&t);
while(t--){
scanf("%s",word);
int len=strlen(word);
getnext(len);
//for(int i=0;i<=len;i++){
//   cout<<next[i];
// }cout<<endl;
scanf("%s",text);
int i=0,j=0;
int len_text=strlen(text);
int cnt=0;
while(i<len_text){
if(j==-1||text[i]==word[j]){
j++,i++;
}
else j=next[j];
//  cout<<j<<endl;
if(j==len) j=next[j],cnt++;
}
printf("%d\n",cnt);
}

return 0;
}