POJ 2083 Fractal：分形&分治

POJ 2083 Fractal：分形&分治2014-07-20 synapse7 Fractal

http://poj.org/problem？id=2083

Time Limit: 1000MS

Memory Limit: 30000K

Description

A fractal is an object or quantity that displays self-similarity, in a somewhat technical sense, on all scales. The object need not exhibit exactly the same structure at all scales, but the same "type" of structures must appear on all scales.A box fractal is defined as below :

A box fractal of degree 1 is simply X

A box fractal of degree 2 is X X X X X

If using B（n - 1） to represent the box fractal of degree n - 1, then a box fractal of degree n is defined recursively as following

B（n - 1） B（n - 1） B（n - 1）B（n - 1） B（n - 1）

Your task is to draw a box fractal of degree n.

Input

The input consists of several test cases. Each line of the input contains a positive integer n which is no greater than 7. The last line of input is a negative integer 1 indicating the end of input.

Output

For each test case, output the box fractal using the "X" notation. Please notice that "X" is an uppercase letter. Print a line with only a single dash after each test case.

Sample Input

1234-1

Sample Output

X-X X XX X-X X X X X XX X X X X X X X XX X X X X XX X X X-X X X X X X X X X X X XX X X X X X X X X X X X X X X X X XX X X X X X X X X X X XX X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X XX X X X X X X X X X X XX X X X X X X X X X X X X X X X X XX X X X X X X X X X X XX X X X X X X X-

Source

Shanghai 2004 Preliminary