TopCoder problem "FunctionalEquation" used in SRM 456 (Division I Level Three)



Problem Statement

    f is a function from integers to integers. In other words, f is defined over integers, and f(x) is an integer for all integers x. You are given an integer C. f is called C-beautiful if the following equality is satisfied for all integers x:







Return the minimal possible value of the following formula when f is C-beautiful:







Use the following recursive definitions to generate the sequences x and y:
  • x[0] = xzero
  • For all integer i between 1 and N-1, inclusive, x[i] = (x[i-1] * xprod + xadd) % xmod
  • y[0] = yzero
  • For all integer i between 1 and N-1, inclusive, y[i] = (y[i-1] * yprod + yadd) % ymod
 

Definition

    
Class:FunctionalEquation
Method:minAbsSum
Parameters:int, int, int, int, int, int, int, int, int, int
Returns:long
Method signature:long minAbsSum(int C, int N, int xzero, int xprod, int xadd, int xmod, int yzero, int yprod, int yadd, int ymod)
(be sure your method is public)
    
 

Notes

-64-bit integers should be used to generate the sequences x and y to avoid overflow.
 

Constraints

-C will be between 1 and 16, inclusive.
-N will be between 1 and 10,000, inclusive.
-xmod and ymod will each be between 1 and 1,000,000,000, inclusive.
-xzero, xprod and xadd will each be between 0 and xmod - 1, inclusive.
-yzero, yprod and yadd will each be between 0 and ymod - 1, inclusive.
 

Examples

0)
    
3
10
0
1
1
456
1
1
1
456
Returns: 0
f(x) = x + 1 is a 3-beautiful function.

Since x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} and y = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, the sum of |f(x[i]) - y[i]| is 0.
1)
    
4
10
0
1
1
456
1
1
1
456
Returns: 5
x and y are the same as in example 0, but f(x) = x + 1 is not a 4-beautiful function.
2)
    
16
10000
654816386
163457813
165911619
987654321
817645381
871564816
614735118
876543210
Returns: 3150803357206

Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=10570

Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=13909&pm=10570

Writer:

rng_58

Testers:

PabloGilberto , misof , ivan_metelsky

Problem categories:

Graph Theory, Math