#codejam problem

A R x C matrix of positive numbers wraps around a drum. Each number represents the number of cells that share an edge with the cell of the same number. For eg the front and back of the drum can be :

3  3  3

3  3  3

2  2  2

The top and bottom of the drum can be different so the line containing 2 can appear in the first line instead of the last and this will make it a different arrangement. If an arrangement can be rotated to get another, they are the same. How many different arrangements exist for given R x C

const int a[5][6]={1,1,4,1,1,10,2,2,2,6,2,2,1,1,7,1,1,19,1,1,7,9,1,19,2,2,14,10,2,92};

int GetMinArrangements(int R, int C)

{

assert(R > 0 && C> 0);

Int answer = 0;

For (int I = 1; I <= C; i++)

{

    Int d = gcd(C, i)

    answer += a[R-2][d-1];

}

return answer/C;

}

 

Int gcd(int x, int y)

{

If y == 0 return x;

return gcd(y, x % y);

}