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SRM5 Jun 2012
SRM 565

DivisibleSequence

Problem statement, definition, constraints, and public examples.

Problem Statement

A divisible sequence with starting value N and length H is a sequence of positive integers with the following properties:
  • The sequence has H elements, labeled A[0] through A[H-1].
  • A[0] equals N.
  • For each i between 0 and H-2, inclusive, A[i+1] divides A[i].
You are given the ints N and H. Let C be the count of all divisible sequences with starting value N and length H. Return the value (C modulo 1,000,000,009).

Definition

Class:
DivisibleSequence
Method:
count
Parameters:
int, int
Returns:
int
Method signature:
int count(int N, int H)
(be sure your method is public)

Constraints

  • N will be between 1 and 1,000,000,000, inclusive.
  • H will be between 1 and 1,000,000,000, inclusive.

Examples

  1. 5
    3
    Returns: 3
    The three possible sequences are: 5, 5, 5 5, 5, 1 5, 1, 1
  2. 6
    3
    Returns: 9
    The nine possible sequences are: 6, 6, 6 6, 6, 3 6, 6, 2 6, 6, 1 6, 3, 3 6, 3, 1 6, 2, 2 6, 2, 1 6, 1, 1
  3. 10
    2
    Returns: 4
    A[1] can be equal to each of the divisors of the number 10. That is, A[1] can be 1, 2, 5, or 10.
  4. 1
    10000
    Returns: 1
    The only possible sequence consists of all ones.
  5. 30
    4
    Returns: 64
  6. 25883
    100000
    Returns: 991000009
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