Given a string S of length N, find the longest palindromic substring in S. Substring of string S: S[ i . . . . j ] where 0 ≤ i ≤ j < len(S). Palindrome string: A string which reads the same backwards.

Strings are immutable: their value cannot be changed after they are created. When created using String s = "something" they are stored in a special pool in which the same string is stored only once. / ...