Girls' research
Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 65535/32768 K (Java/Others)
Total Submission(s): 4876 Accepted Submission(s): 1822
Problem Description
One day, sailormoon girls are so delighted that they intend to research about palindromic strings. Operation contains two steps:
First step: girls will write a long string (only contains lower case) on the paper. For example, "abcde", but 'a' inside is not the real 'a', that means if we define the 'b' is the real 'a', then we can infer that 'c' is the real 'b', 'd' is the real 'c' ……, 'a' is the real 'z'. According to this, string "abcde" changes to "bcdef".
Second step: girls will find out the longest palindromic string in the given string, the length of palindromic string must be equal or more than 2.
Input
Input contains multiple cases.
Each case contains two parts, a character and a string, they are separated by one space, the character representing the real 'a' is and the length of the string will not exceed 200000.All input must be lowercase.
If the length of string is len, it is marked from 0 to len-1.
Output
Please execute the operation following the two steps.
If you find one, output the start position and end position of palindromic string in a line, next line output the real palindromic string, or output "No solution!".
If there are several answers available, please choose the string which first appears.
Sample Input
b babd a abcd
Sample Output
0 2 aza No solution!
Author
wangjing1111
Source
2010 “HDU-Sailormoon” Programming Contest
Recommend
题意:给你一个字符ch和一个字符串str(只有小写字母),ch代表字符串str中a字符的真身。其余字符类似作此变化。现在让你找出字符串中的最长回文子串,输出回文子串在原字符串的起点和终点,并输出它对应的真身。若有多个满足条件的子串,输出最先出现的。
分析:
马拉车算法的模型,但我尽然卡在了字母变换位置上,总以为一个公式就能出来,一种WA,但是只要分一下情况就很简单了。
对于确定位置的公式,输出一下变长的字符串,在草稿纸上分分情况模拟一下就ok
但我好像推麻烦了,一个int l=(pos-ans+1)/2-1就能解决,这个/2确实巧妙