B. Peculiar Movie Preferences
greedy; strings
Mihai plans to watch a movie. He only likes palindromic movies, so he wants to skip some (possibly zero) scenes to make the remaining parts of the movie palindromic.You are given a list \(s\) of \(n\) non-empty strings of length at most \(3\), representing the scenes of Mihai's movie.A subsequence of \(s\) is called awesome if it is non-empty and the concatenation of the strings in the subsequence, in order, is a palindrome.Can you help Mihai check if there is at least one awesome subsequence of \(s\)?A palindrome is a string that reads the same backward as forward, for example strings ""z"", ""aaa"", ""aba"", ""abccba"" are palindromes, but strings ""codeforces"", ""reality"", ""ab"" are not.A sequence \(a\) is a non-empty subsequence of a non-empty sequence \(b\) if \(a\) can be obtained from \(b\) by deletion of several (possibly zero, but not all) elements.
The first line of the input contains a single integer \(t\) (\(1 \le t \le 100\)) — the number of test cases. The description of test cases follows.The first line of each test case contains a single integer \(n\) (\(1 \le n \le 10^5\)) — the number of scenes in the movie.Then follows \(n\) lines, the \(i\)-th of which containing a single non-empty string \(s_i\) of length at most \(3\), consisting of lowercase Latin letters.It is guaranteed that the sum of \(n\) over all test cases does not exceed \(10^5\).
For each test case, print ""YES"" if there is an awesome subsequence of \(s\), or ""NO"" otherwise (case insensitive).
In the first test case, an awesome subsequence of \(s\) is \([ab, cc, ba]\)