Oulipo（http://acm.hdu.edu.cn/showproblem.php?pid=1686）

Oulipo

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 7715    Accepted Submission(s): 3101

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

 

Source

華東區大學生程序設計邀請賽_熱身賽

#include<cstdio>
#include<cstring>
#define max 10010
int p[max];
char s2[max*100];
char s1[max];
int l1,l2,num;
void getp()//得到p數組，即s1下標的值； 
{
	int i=0,j=-1;//初始 
	p[0]=-1;
	while(i<l1)
	{
		if(j==-1||s1[i]==s1[j])
		{
			i++;
			j++;
			p[i]=j;
		}
		else
		j=p[j];
	}
}
void kmp()
{
	getp();
	int i=0,j=0;
	p[0]=-1;
	while(i<l2)
	{
		if(j==-1||s1[j]==s2[i])
		{
			i++;
			j++;
			if(j==l1)
			{
				num++;
				j=p[j];//標記 
			}
		}
		else
		   j=p[j];
//		if(j==l1)//這個也是對的。 
//		{
//			num++;
//			j=p[j];
//		}
	}
}
int main()
{
	int t;
	scanf("%d",&t);
	while(t--)
	{
		scanf("%s",s1);
		scanf("%s",s2);
		l1=strlen(s1);
		l2=strlen(s2);
		num=0;
		kmp();
		printf("%d\n",num);
	}
	return 0;
}