Oulipo_poj_3461_KMP水题

Oulipo

Time Limit: 1000MS Memory Limit: 65536KTotal Submissions: 39582 Accepted: 15932

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

题意：给你 t 组数据，每组给你一个小段字符，再给你一个大段字符，问你小段字符能在大段里出现多少次。

思路：字符串匹配呗，重复的部分也算上，直接KMP，没什么要讲咯。

代码：

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>using namespace std;const int maxn=1e7+5;int pl,sl;char s[maxn],p[maxn];int next[maxn];int sum;void get_next(){    int k=-1,j=0;    next[0]=-1;    while(j<pl)    {        if(k==-1||p[j]==p[k])        {            j++;k++;            next[j]=k;        }        else        k=next[k];    }}int KMP(){    int i=0,j=0;    get_next();    while(j<pl&&i<sl)    {            if(j==-1||s[i]==p[j])            {                i++;j++;            }            else j=next[j];            if(j==pl)            {                sum++;j=next[j];            }    }    return sum;}int main(){    int t;    while(~scanf("%d",&t))    {        while(t--)        {            sum=0;            scanf("%s",p);            scanf("%s",s);            pl=strlen(p);            sl=strlen(s);            int ans=KMP();            printf("%d\n",ans);        }    }    return 0;}