HDU 5763 Another Meaning (kmp + dp)
Another Meaning
题目链接:
http://acm.hdu.edu.cn/showproblem.php?pid=5763
Description
As is known to all, in many cases, a word has two meanings. Such as “hehe”, which not only means “hehe”, but also means “excuse me”.
Today, ?? is chating with MeiZi online, MeiZi sends a sentence A to ??. ?? is so smart that he knows the word B in the sentence has two meanings. He wants to know how many kinds of meanings MeiZi can express.
Input
The first line of the input gives the number of test cases T; T test cases follow.
Each test case contains two strings A and B, A means the sentence MeiZi sends to ??, B means the word B which has two menaings. string only contains lowercase letters.
Limits
T <= 30
|A| <= 100000
|B| <= |A|
Output
For each test case, output one line containing “Case #x: y” (without quotes) , where x is the test case number (starting from 1) and y is the number of the different meaning of this sentence may be. Since this number may be quite large, you should output the answer modulo 1000000007.
Sample Input
4
hehehe
hehe
woquxizaolehehe
woquxizaole
hehehehe
hehe
owoadiuhzgneninougur
iehiehieh
Sample Output
Case #1: 3
Case #2: 2
Case #3: 5
Case #4: 1
Hint
In the first case, “ hehehe” can have 3 meaings: “he”, “he”, “hehehe”.
In the third case, “hehehehe” can have 5 meaings: “hehe”, “hehe”, “hehe*”, “**”, “hehehehe”.
Source
2016 Multi-University Training Contest 4
##题意: 给出字符串A和B,单词B具有两种解释,求字符串A一共有多少种意义.
##题解: 考虑A中每个单词B,需要考虑它是否解释为第二种意义;很显然要用DP. 首先用kmp处理出A中的每个B,记录每个B的起点和终点(下面的代码记录的是以i为终点的B的起点,没有则为-1). dp[i]为处理到第i个字符时共有多少种意义: 若i是某个B的终点,则dp[i] = dp[i-1] + dp[起点-1]. (前者为当前B不解释为二义,后者为把B解释为二义). 若i不是终点,则dp[i] = dp[i-1];
值得一提的是:由于背包dp需要用到初始值dp[0],而字符串又从0开始,导致初始值为dp[-1],所以下面的代码特别处理了这个问题. 实际上,应该在读入字符串时空出str[0]来避免这个问题.
##代码: ``` cpp #include