topcoder : SRM 571 Div 1 Problem :250

FoxAndMp3.java

/*
 * @author rohit jangid
 * @data Apr 16, 2013
 * @file-name FoxAndMp3.java
 * @license this code is licensed under WTFPL V-2.0
 * @details Topcoder SRM 571 Div I problem 250
 */


import java.util.Arrays;

public class FoxAndMp3 {

  public int calculate(int index, int t, int n, String[] play) {
		int i = t;
		while(i <= t + 9 && i <= n && index < 50) {
			play[index++] = i + ".mp3";
			index = calculate(index, i*10, n, play);
			i++;
		}
		return index;
	}
	public String[] playList(int n) {
		String[] play = new String[50];
		int i = 1;
		int index = 0;
		while(i <= 9 && i <= n && index < 50) {
			play[index++] = i + ".mp3";
			index = calculate(index, i*10,n,play);
			i++;
			
		}
		if(n < 50) {
			String[] playlist = new String[n];
			for(i =0; i<n; i++) {
				playlist[i] = play[i];
			}
			return playlist;
		}
		else return play;
	}
}