题目链接:
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 iehiehiehSample Output
Case #1: 3
Case #2: 2 Case #3: 5 Case #4: 1Hint
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:
#include#include #include #include #include #include #include