HDU 3695 Computer Virus on Planet Pandora (AC自動機)
來源：程序員人生 發布時間：2015-03-19 08:34:21 閱讀次數：3528次
Computer Virus on Planet Pandora
Time Limit: 6000/2000 MS (Java/Others) Memory Limit: 256000/128000 K (Java/Others)
Total Submission(s): 2879 Accepted Submission(s): 808
Problem Description
Aliens on planet Pandora also write computer programs like us. Their programs only consist of capital letters (‘A’ to ‘Z’) which they learned from the Earth. On
planet Pandora, hackers make computer virus, so they also have anti-virus software. Of course they learned virus scanning algorithm from the Earth. Every virus has a pattern string which consists of only capital letters. If a virus’s pattern string is a substring
of a program, or the pattern string is a substring of the reverse of that program, they can say the program is infected by that virus. Give you a program and a list of virus pattern strings, please write a program to figure out how many viruses the program
is infected by.
Input
There are multiple test cases. The first line in the input is an integer T ( T<= 10) indicating the number of test cases.
For each test case:
The first line is a integer n( 0 < n <= 250) indicating the number of virus pattern strings.
Then n lines follows, each represents a virus pattern string. Every pattern string stands for a virus. It’s guaranteed that those n pattern strings are all different so there
are n different viruses. The length of pattern string is no more than 1,000 and a pattern string at least consists of one letter.
The last line of a test case is the program. The program may be described in a compressed format. A compressed program consists of capital letters and
“compressors”. A “compressor” is in the following format:
[qx]
q is a number( 0 < q <= 5,000,000)and x is a capital letter. It means q consecutive letter xs in the original uncompressed program. For example, [6K] means
‘KKKKKK’ in the original program. So, if a compressed program is like:
AB[2D]E[7K]G
It actually is ABDDEKKKKKKKG after decompressed to original format.
The length of the program is at least 1 and at most 5,100,000, no matter in the compressed format or after it is decompressed to original format.
Output
For each test case, print an integer K in a line meaning that the program is infected by K viruses.
Sample Input
3
2
AB
DCB
DACB
3
ABC
CDE
GHI
ABCCDEFIHG
4
ABB
ACDEE
BBB
FEEE
A[2B]CD[4E]F
Sample Output
0
3
2
Hint
In the second case in the sample input, the reverse of the program is ‘GHIFEDCCBA’, and ‘GHI’ is a substring of the reverse, so the program is infected
by virus ‘GHI’.
Source
2010 Asia Fuzhou Regional Contest
題目鏈接：http://acm.hdu.edu.cn/showproblem.php?pid=3695
題目大意：求不同的單詞或其倒敘在文章中出現的次數，文章可能以緊縮的情勢展現，[qx]表示連續'x'個q
題目分析：由于要斟酌倒敘，能想到兩種方案，1個是用單詞和其倒敘構建字典樹，由于這題數據量太大，這樣會MLE，只能采取第2種方法，將文章正序匹配1次再倒敘匹配1次，在這里我用了1句while(i < (int)strlen(get)) {...}由于這個T了1下午，改成int l =
strlen(get);
while(i < l) {...}就好了，不明白為何
