TopcoderArchive
SRM2 Nov 2006
SRM 325

NewMoneySystem

Problem statement, definition, constraints, and public examples.

Problem Statement

You are creating the money system for a new game. The requirements are as follows:

  1. There will be exactly K different banknote values.
  2. The value of the smallest banknote will be equal to one dollar.
  3. The value of the i-th banknote will be equal to the value of the (i-1)-th banknote multiplied by 2, 3, 4 or 5.

The initial capital of a player will be N dollars, so you want to choose banknote values in such a way that minimizes the number of banknotes required to make N dollars. Assume that you have an infinite supply of banknotes for each value.

You will be given two integers N and K. Due to technical reasons, N will be given as a String with no leading zeros. Return the minimal number of banknotes required to make exactly N dollars. Note that you must minimize the number of actual banknotes, not the number of banknote values (see examples).

Definition

Class:
NewMoneySystem
Method:
chooseBanknotes
Parameters:
String, int
Returns:
long
Method signature:
long chooseBanknotes(String N, int K)
(be sure your method is public)

Constraints

  • N will be an integer between 1 and 1018, inclusive, with no leading zeros.
  • K will be between 1 and 100, inclusive.

Examples

  1. "1025"
    6
    Returns: 2
    The best set of banknote values is {1, 4, 16, 64, 256, 1024}. 1025 = 1024 + 1.
  2. "1005"
    5
    Returns: 3
    The best set of banknote values is {1, 5, 25, 100, 500}. 1005 = 2 * 500 + 5.
  3. "12000"
    14
    Returns: 1
  4. "924323565426323626"
    1
    Returns: 924323565426323626
    The answer can be rather big.
  5. "924323565426323626"
    50
    Returns: 10
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