HDU 1686 Oulipo【KMP模板题】

Oulipo

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 14707    Accepted Submission(s): 5803

Problem 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

130

 

题意概括：

判断第二个串在第一个串中出现的次数。

解题分析：

这题就是一道比较水的KMP。话不多说，上代码。

AC代码：

#include<stdio.h>#include<string.h>const int N = 100005, M = 1000005;int next[N];void get_next(char *s){    int i = 1, j = 0, len = strlen(s);    while(s[i]){        if(!j && s[i] != s[j]){            next[i] = 0;            i++;        }        else if(j && s[i] != s[j])            j = next[j-1];        else{            next[i] = j+1;            i++;            j++;        }    }}int KMP(char *s1, char *s2){    int i = 0, j = 0, coun = 0, len = strlen(s1);    get_next(s1);    while(s2[i]){        if(!j && s1[j] != s2[i])            i++;        else if(j && s1[j] != s2[i])            j = next[j-1];        else{            i++;            j++;        }        if(j == len)            coun++;    }    return coun;}int main(){    int T;    char s1[N], s2[M];    scanf("%d",&T);    while(T--){        scanf("%s%s", s1, s2);        printf("%d\n", KMP(s1,s2));    }    return 0;}