P16624 [CodeChef] SUBSTRING
普及
题目描述

Shefin gives you a string S and you have to find a non-empty string P such that:
P is a substring of S.
No non-empty substring of P is a prefix of S.
No non-empty substring of P is a suffix of S.

For all such possible strings, find the length of the longest string satisfying all the conditions. If no such string is possible, print -1.

A string A is a substring of a string B if A can be obtained from B by deleting several (possibly zero) characters from the beginning and several (possibly zero) characters from the end.
A prefix of a string A, is a substring of A that occurs at the beginning of A. For example, "code" is a prefix of "codechef", but "ode" is not.
A suffix of a string A, is a substring of A that occurs at the end of A. For example, "chef" is a suffix of "codechef", but "he" is not.

------ Input Format ------

  • The first line of the input contains an integer T - denoting number of test cases.
  • Each test case contains a string S consisting of lowercase english alphabets only.

------ Output Format ------

For each test case, print a single integer. If a string P exists based on the given conditions, print the maximum length of the possible string. Otherwise, print -1.

------ Constraints ------

${1 ≤T ≤10^{4}}$
${1 ≤\lvert S \rvert ≤10^{6}}$
- Sum of ${\lvert S \rvert}$ over all test cases does not exceed $10^{6}$.
$S$ consists of lowercase english alphabets only.

----- Sample Input 1 ------
2
abcdab
aaa

----- Sample Output 1 ------
2
-1

----- explanation 1 ------
Test Case $1$: The maximum length of the string satisfying all required conditions is $2$. The string $\texttt{cd}$ satisfies all the conditions. It can be proven that no string of length greater than $2$ exists which can satisfy all the conditions.

Test Case $2$: There is no string possible which satisfies all the required conditions. Thus, the answer is $-1$.

输入格式

见题面

输出格式

见题面

样例输入
2 abcdab aaa
样例输出
2 -1