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POJ3461 Oulipo

 

Oulipo
Time Limit: 1000MS Memory Limit: 65536K
Total Submissions: 36441 Accepted: 14728

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

BAPC 2006 Qualification

 

问字符串2中包含多少个字符串1。

KMP匹配即可

 1 /**/ 2 #include<iostream> 3 #include<cstdio> 4 #include<cmath> 5 #include<cstring> 6 #include<algorithm> 7 using namespace std; 8 const int mxn=1000020; 9 char s[mxn];10 char a[10020];11 int next[mxn];12 int f[mxn];13 int lens,lena;14 void gne(){15     next[0]=-1;16     int i,j=-1;17     for(i=1;i<lena;i++){18         while(j>=0 && a[j+1]!=a[i])j=next[j];19         if(a[j+1]==a[i])j++;20         next[i]=j;21     }22     return;23 }24 int main(){25     int T;26     scanf("%d",&T);27     int i,j;28     while(T--){29         scanf("%s%s",a,s);30         lena=strlen(a);31         lens=strlen(s);32         gne();33         j=-1;34         int ans=0,last=0;35         for(i=0;i<lens;i++){36             while(j>=0 && a[j+1]!=s[i])j=next[j];37             if(a[j+1]==s[i])j++;38             f[i]=j;39             if(f[i]==lena-1){40                 ans++;41                 j=next[j];42             }43         }44         printf("%d\n",ans);45     }46     return 0;47 }

 

POJ3461 Oulipo