HDU 1686-Oulipo

Oulipo

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 16570    Accepted Submission(s): 6636

题目链接：点击打开链接

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
1
3
0

题意：

题目太长了，看一眼测试测试数据，瞬间懂了，提交就对了，说明猜的没错并且题目没有坑。题目就是给你两个串然你在第二个串里找第一个串最大的匹配值，即能找到多少个和第一个串一样的串

分析：

KMP算法。

#include<stdio.h>#include<string>#include<string.h>const int INF1=10005;const int INF2=1000005;char a[INF1],b[INF2];int next[INF1];int m,n;void get_next(){    next[0] = -1;    int k = -1;    for (int i = 1; i < m; i++)    {        while (k > -1 && a[k + 1] != a[i])        {            k = next[k];        }        if (a[k + 1] == a[i])        {            k = k + 1;        }        next[i] = k;    }}int KMP(){    get_next();    int k = -1;    int sum=0;    for (int i = 0; i < n;i++ )    {        while (k >-1&& a[k + 1] != b[i])        {            k = next[k];        }        if (a[k + 1] == b[i])            k = k + 1;        if (k == m-1)        {            sum++;        }    }    return sum;}int main(){    int t;    scanf("%d",&t);    while(t--)    {        scanf("%s",a);        scanf("%s",b);        m=strlen(a);        n=strlen(b);        int sum=KMP();        printf("%d\n",sum);    }    return 0;}