You are given a circle of diameter d, with n points equally spaced around the circumference. The points are numbered in order around the circle 0, 1, 2, ... , n-1. Of those n points, c of them are colored red. The points that are colored red are given by the generator function (g * k) % n, for k = 0, 1, 2, ..., c-1.
You are given ints d, n, c, and g. You are to return a double indicating the largest area of a quadrilateral formed from four of the colored points.
|-||The % operator is the modulus (remainder) operator.|
|-||Notice that it makes no difference which point is point 0, and in which direction around the circle the points are numbered.|
|-||d will be between 1 and 1000, inclusive.|
|-||n will be between 4 and 1000000000, inclusive.|
|-||c will be between 4 and 500, inclusive.|
|-||c will be less than or equal to n.|
|-||g will be between 1 and n-1, inclusive, and will be relatively prime to n.|