Preparing NOJ

# Period

3000ms 30000K

## Description:

For each prefix of a given string S with N characters (each character has an ASCII code between 97 and 126, inclusive), we want to know whether the prefix is a periodic string. That is, for each i (2 <= i <= N) we want to know the largest K > 1 (if there is one) such that the prefix of S with length i can be written as AK ,that is A concatenated K times, for some string A. Of course, we also want to know the period K.

## Input:

The input consists of several test cases. Each test case consists of two lines. The first one contains N (2 <= N <= 1 000 000) – the size of the string S.The second line contains the string S. The input file ends with a line, having the
number zero on it.

## Output:

For each test case, output "Test case #" and the consecutive test case number on a single line; then, for each prefix with length i that has a period K > 1, output the prefix size i and the period K separated by a single space; the prefix sizes must be in increasing order. Print a blank line after each test case.

## Sample Input:

3
aaa
12
aabaabaabaab
0

## Sample Output:

Test case #1
2 2
3 3

Test case #2
2 2
6 2
9 3
12 4

Info

Provider POJ

Origin Southeastern Europe 2004

Code POJ1961

Tags

Submitted 20

Passed 5

AC Rate 25%

Date 03/06/2019 15:25:10

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