301773: CF335B. Palindrome
Memory Limit:256 MB
Time Limit:2 S
Judge Style:Text Compare
Creator:
Submit:0
Solved:0
Description
Palindrome
题意翻译
题面: 给你一个字符串 $s$,确认它是否包含有长度为 $100$ 的回文子序列,如果有,输出其中一个;如果没有,输出它所包含的最长回文子序列。 输入: 一个长度为 $n$($1 \le n \le 5 \times {10}^4$)的字符串 $s$。 输出: 如果它有长度为 $100$ 的回文子序列,输出其中一种;否则输出其包含的最长回文子序列。 提示: 一个字符串的子序列可以通过删除原字符串中**任意字符**而**不改变**原本字符顺序产生。 感谢 @\_\_\_\_233\_\_\_\_ 提供的翻译题目描述
Given a string $ s $ , determine if it contains any palindrome of length exactly $ 100 $ as a subsequence. If it has any, print any one of them. If it doesn't have any, print a palindrome that is a subsequence of $ s $ and is as long as possible.输入输出格式
输入格式
The only line of the input contains one string $ s $ of length $ n $ ( $ 1<=n<=5·10^{4} $ ) containing only lowercase English letters.
输出格式
If $ s $ contains a palindrome of length exactly $ 100 $ as a subsequence, print any palindrome of length $ 100 $ which is a subsequence of $ s $ . If $ s $ doesn't contain any palindromes of length exactly $ 100 $ , print a palindrome that is a subsequence of $ s $ and is as long as possible. If there exists multiple answers, you are allowed to print any of them.
输入输出样例
输入样例 #1
bbbabcbbb
输出样例 #1
bbbcbbb
输入样例 #2
rquwmzexectvnbanemsmdufrg
输出样例 #2
rumenanemur