TopcoderArchiveVisit Topcoder
SRM25 May 2011
SRM 523

CountingSeries

Problem statement, definition, constraints, and public examples.

Problem Statement

You are given longs a, b, c and d. The numbers a and b define an arithmetic progression that consists of all numbers of the form a + b*x, where x is a nonnegative integer. Likewise, c and d define a geometric progression that consists of all the numbers that are equal to c * d^y, where y is a nonnegative integer. You are also given a long upperBound. Return the total number of integers between 1 and upperBound, inclusive, that belong to the arithmetic progression, the geometric progression or both.

Definition

Class:
CountingSeries
Method:
countThem
Parameters:
long, long, long, long, long
Returns:
long
Method signature:
long countThem(long a, long b, long c, long d, long upperBound)
(be sure your method is public)

Notes

  • The ^ operator in this statement denotes the exponentiation operation. For example, 3^0 = 1 and 2^4 = 2*2*2*2 = 16.

Constraints

  • a, b, c and upperBound will each be between 1 and 1000000000000 (10^12), inclusive.
  • d will be between 1 and 100000 (10^5), inclusive.

Examples

  1. 1
    1
    1
    2
    1000
    Returns: 1000
    The arithmetic progression is: 1, 2, 3, 4, ... . The geometric progression is: 1, 2, 4, 8, 16, ... . Each positive integer is contained in at least one of the progressions.
  2. 3
    3
    1
    2
    1000
    Returns: 343
    This time, the arithmetic progression is: 3, 6, 9, 12, ... . The geometric progression is still: 1, 2, 4, 8, 16, .... There are 333 multiples of 3 between 1 and 1000, inclusive, and there are 10 powers of 2, 512 being the highest. As these two progressions do not have any common elements, the total result is 343.
  3. 40
    77
    40
    100000
    40
    Returns: 1
  4. 452
    24
    4
    5
    600
    Returns: 10
    The 10 numbers are: 4, 20, 100, 452, 476, 500, 524, 548, 572 and 596.
  5. 234
    24
    377
    1
    10000
    Returns: 408
Back to all problems