B. Lovely Palindromes1000 / 构造 找规律

Posted 2021-10-09 幽殇默

https://codeforces.com/problemset/problem/688/B
打表，你会发现，输入的东西翻转后拼接起来就是第n个

#include<bits/stdc++.h>
using namespace std;
int main(void)
{
	string s; cin>>s;
	string ans=s;
	reverse(s.begin(),s.end());
	ans+=s;
	cout<<ans;
	return 0;
}