Time Limit: 1000MS | Memory Limit: 65536K | |
Total Submissions: 37958 | Accepted: 15282 |
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
#include <cstdio> #include <string> #include <cstring> #include <iostream> #include <algorithm> using namespace std; int ls,lt,T,next[1000001]; char s[1000001],t[1000001]; inline void GetNext() { //memset(next,0,sizeof(next)); int k=-1,j=0; next[j]=k; while(j<lt) { if(k==-1||t[j]==t[k]) { k++,j++; next[j]=k; } else k=next[k]; } } inline int Kmp() { GetNext(); int i=0,j=0,return_=0; while(i<ls) { if(j==-1||s[i]==t[j]) i++,j++; else j=next[j]; if(j==lt) { j=next[j]; return_++; } } return return_; } int main() { scanf("%d",&T); for(int i=1;i<=T;i++) { cin>>t; cin>>s; ls=strlen(s); lt=strlen(t); cout<<Kmp()<<endl; } return 0; }