点击打开链接

Oulipo

Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 4004 Accepted Submission(s): 1580

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

3
BAPC
BAPC
AZA
AZAZAZA
VERDI
AVERDXIVYERDIAN

Sample Output

1
3
0

Source 华东区大学生程序设计邀请赛_热身赛

//109MS	1252K
#include
  
   
#include
   
     char text[1000007],pattern[10007]; int next[10007],n,m; void pre() { next[0]=-1; int j=-1; for(int i=1;i
    
     =0&&pattern[j+1]!=pattern[i])j=next[j]; if(pattern[j+1]==pattern[i])j++; next[i]=j; } } int kmp() { int ans=0,j=-1; for(int i=0;i
     
      =0&&pattern[j+1]!=text[i])j=next[j]; if(pattern[j+1]==text[i])j++; if(j==m-1)ans++; } return ans; } int main() { int t; scanf("%d",&t); while(t--) { scanf("%s%s",pattern,text); m=strlen(pattern); n=strlen(text); pre(); printf("%d\n",kmp()); } return 0; }

HDU 2087 Oulipo kmp入门

Oulipo