poj 3461 Oulipo,裸kmp

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Oulipo

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 32373		Accepted: 13093

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

 

 

15266997

njczy2010

3461

Accepted

1736K

125MS

G++

1147B

2016-03-14 17:00:52

 

题意：

裸的kmp

 

代码：

 #include <iostream>
 #include <cstdio>
 #include <map>
 #include <cstring>
 #include <algorithm>

 using namespace std;

 #define N 1000005
 #define ll long long

 int TT;
 char s[N];
 char t[N];
 int next[N];
 int ans;
 int l;
 int lt;

 void get_next()
 {
     int i,j;
     i = ;
     j = -;
     next[] = -;
     while(i<l)
     {
         if(j == - || s[i] == s[j]){
             i++;j++;next[i] = j;
         }
         else{
             j = next[j];
         }
     }
 }

 void kmp()
 {
     int i,j;
     i = ;
     j = ;
     while(i < lt)
     {
         if(j == - || t[i] == s[j]){
             if(j == l - ){
                 ans ++;
                 j = next[j];
             }
             else{
                 i++;j++;
             }
         }
         else{
             j = next[j];
         }
     }
 }

 int main()
 {
     //freopen("in.txt","r",stdin);
     //freopen("out.txt","w",stdout);
     scanf("%d",&TT);
     while(TT--){
     //while(scanf("%I64d%I64d",&n,&k)!=EOF){
         ans = ;
         scanf("%s",s);
         l = strlen(s);
         scanf("%s",t);
         lt = strlen(t);
         get_next();
         kmp();
         printf("%d\n",ans);
     }
     return ;
 }