Problem Brief

Find Longest Palindromic Substring 🌼

INTERNOA

The input consists of a string inputStr, representing the given string for the puzzle.

From the given string, print a substring which is the same when read forwards and backwards.

Note

If there are multiple sub-strings of equal length, choose the lexicographically smallest one.
If there are multiple sub-strings of different length, choose the one with maximum length.
If there is no sub-string that is the same when read forwards and backwards print "None".
Sub-string is only valid if its length is more than 1.
Strings only contain uppercase characters (A-Z).

1Example 1

Input

inputStr = "YABCCBAZ"

Output

"ABCCBA"

Explanation

Given string is "YABCCBAZ", in this only sub-string which is same when read forward and backward is "ABCCBA".

Input

inputStr = "ABC"

Output

"None"

Explanation

Given string is "ABC", and no sub-string is present which is same when read forward and backward. So, the output is "None".

Limits and guarantees your solution can rely on.

Unknown for now

Draft autosaves locally

public String longestPalindrome(String inputStr) {
    // write your code here
}

Input

inputStr

"YABCCBAZ"

Output

"ABCCBA"