HDUOJ -----1686

时间:2022-05-05
本文章向大家介绍HDUOJ -----1686,主要内容包括其使用实例、应用技巧、基本知识点总结和需要注意事项,具有一定的参考价值,需要的朋友可以参考一下。

Oulipo

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 3770    Accepted Submission(s): 1485

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

kmp   ....经典题

思路清晰,就不多说啦!...

就是求目标串在主串中出现几次,即匹配几次,,.

代码:

 1 /*@coder 龚细军*/
 2 #include<iostream>
 3 #include<string>
 4 #include<vector>
 5 using namespace std;
 6 
 7 int main()
 8 {
 9     int t,i,j;
10     string pw,ps;
11     cin>>t;
12     while(t--)
13     {
14         i=0,j=-1;
15         cin>>pw>>ps;   /*pw作为目标串,ps作为主串*/
16         int lenpw=pw.length();
17         int lenps=ps.length();
18         vector<int>next(lenpw+1,0);
19         next[i]=-1;
20         while(i<lenpw)
21         {
22             if(j==-1||pw[i]==pw[j])
23             {
24                 ++i;
25                 ++j;
26                 if(pw[i]!=pw[j])
27                     next[i]=j;
28                 else
29                     next[i]=next[j];
30             }
31             else
32                 j=next[j];
33         }
34         i=-1,j=-1;
35         int ans=0;
36         while(i<lenps)
37         {
38             if(j==-1||pw[j]==ps[i])
39             {
40                 ++i;
41                 ++j;
42             }
43             else
44                 j=next[j];
45          if(j==lenpw)
46              ans++;
47         }
48         printf("%dn",ans);
49     }
50   return 0;
51 }