UVA - 10880 - Colin and Ryan

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.LinkedList;

public class Main {

    public static void main(String[] args) throws IOException {
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);
        StringBuffer sb = new StringBuffer("");
        int n = Integer.parseInt(br.readLine());
        String m = "";
        for (int i = 1; i < n + 1; i++) {
            String[] str = br.readLine().split(" ");
            int x = Integer.parseInt(str[0]);
            int y = Integer.parseInt(str[1]);
            long arr[] = div(x - y, y);
            sb.append("Case #").append(i).append(":");
            for (int j = 0; j < arr.length; j++) {
                sb.append(" ").append(arr[j]);
            }
            sb.append("\n");
        }
        System.out.print(sb);
    }

    static long[] div(int x, int r) {
        LinkedList<Long> list = new LinkedList<Long>();
        long[] arr;
        if (x==0) {
            arr = new long[1];
            arr[0] = 0;
            return arr;
        }
        if (r > x) {
            return new long[0];
        }
        for (long i = 1; i < Math.sqrt(x) + 1; i++) {
            if (x % i == 0) {
                if (i > r && !list.contains(i)) {
                    list.add(i);
                }
                if ((x / i) > r) {
                    if(!list.contains(x/i))
                        list.add(x / i);
                }
            }
        }
        arr = new long[list.size()];
        for (int i = 0; i < list.size(); i++) {
            arr[i] = list.get(i);
        }
        Arrays.sort(arr);
        return arr;
    }
}