算法：全组合算法

    public static List<int[]> combin(final int TOTAL, final int SELETED) {
        List<int[]> list = new ArrayList<int[]>(400000);
        int[] i = new int[SELETED];
        for (int x = 1; x <= SELETED; x++)
            i[x - 1] = x;
        final int LAST = SELETED - 1;
        while (true) {
            list.add(Arrays.copyOf(i, SELETED));
            i[LAST]++;
            for (int n = LAST; n > 0; n--) {
                //i[n]达到顶点
                if (i[n] > TOTAL - SELETED + 1 + n) {
                    i[n - 1]++;
                    for (int x = n; x < SELETED; x++) {
                        i[x] = i[x - 1] + 1;
                    }
                }
            }
            if (i[0] == TOTAL - LAST + 1) {
                break;
            }
        }
        return list;
        // return null;
    }

    public static void main(String[] args) {
        long i = System.currentTimeMillis();
        List<int[]> list = combin(36, 5);
        System.out.println(System.currentTimeMillis() - i);
        System.out.println(list.size());
    }