POJ 3461 Oulipo (KMP字符串匹配·统计p在s中出现次数)

题意  给你两个字符串p和s  求p在s中出现的次数  很裸的kmp

因为不止匹配一次  每次找到后还要循环j=next[j]的过程   知道到达s的终点

#include<cstdio>#include<cstring>using namespace std;const int N = 10005, M = 1000005;int next[N], ans, n;char p[N], s[M];void kmp (){    int lp = strlen (p), ls = strlen (s);    int i, j;    //求next数组    i = 0;    j = next[0] = -1;    while (i < lp)    {        if(j == -1 || p[i] == p[j])            next[++i] = ++j;        else j = next[j];    }    //kmp匹配    i = j = 0;    while (i < ls)    {        if (j == -1 || s[i] == p[j])        {            ++i, ++j;            if (j == lp) ++ans, j = next[j];        }        else j = next[j];    }}int main(){    scanf ("%d", &n);    while (n--)    {        ans = 0;        scanf ("%s%s", p, s);        kmp ();        printf ("%d\n", ans);    }    return 0;}

Oulipo

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