Kalindrome Array solution codeforces
An arrayis a palindrome, if for each from to . Empty array is also a palindrome.
An array is called kalindrome, if the following condition holds:
- It’s possible to select some integer and delete some of the elements of the array equal to , so that the remaining array (after gluing together the remaining parts) is a palindrome.
Note that you don’t have to delete all elements equal to, and you don’t have to delete at least one element equal to .
For example : Kalindrome Array solution codeforces
- is kalindrome because you can simply not delete a single element.
- is kalindrome because you can choose and delete both elements equal to , obtaining array , which is a palindrome.
- is not kalindrome.
You are given an array. Determine if is kalindrome or not.
The first line contains a single integer( ) — the number of test cases. The description of the test cases follows.
The first line of each test case contains a single integer( ) — the length of the array.
The second line of each test case containsintegers ( ) — elements of the array.
It’s guaranteed that the sum ofover all test cases won’t exceed .
For each test case, print YES if is kalindrome and NO otherwise. You can print each letter in any case.
4 1 1 2 1 2 3 1 2 3 5 1 4 4 1 4
output Kalindrome Array solution codeforces
YES YES NO YES
In the first test case, arrayis already a palindrome, so it’s a kalindrome as well.
In the second test case, we can choose, delete the second element, and obtain array , which is a palindrome.
In the third test case, it’s impossible to obtain a palindrome.
In the fourth test case, you can chooseand delete the fifth element, obtaining . You also can choose , delete the first and the fourth elements, and obtain .