(简单kmp) Oulipo (p3461)

#include<iostream>#include<cstdio>#include<algorithm>#include<queue>#include<vector>#include<cmath>#include<set>#include<cstring>using namespace std;#define N 1000001char a[N],b[N];int next[N];int la,lb;int main(){//freopen("in.txt","r",stdin);int i,j,k;int t;cin>>t;while (t--){cin>>a>>b;la=strlen(a);lb=strlen(b);j=-1;next[0]=j;i=0;while (i<la){if (j==-1||a[j]==a[i]){j++;i++;next[i]=j;}elsej=next[j];}int ans=0;i=0;j=0;while (i<lb){if (j<la&&(j==-1||a[j]==b[i])){j++;i++;if (j==la)ans++;}elsej=next[j];}cout<<ans<<endl;}return 0;}

Oulipo

Time Limit: 1000MS Memory Limit: 65536KTotal Submissions: 12059 Accepted: 4799

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 wordW and a text T, count the number of occurrences of W inT. All the consecutive characters of W must exactly match consecutive characters ofT. 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 stringW).
• 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 wordW in the text T.

Sample Input

3BAPCBAPCAZAAZAZAZAVERDIAVERDXIVYERDIAN

Sample Output

130

Source