public static Fraction AngleBetween(Pos p1, Pos p2)
{
return(new Fraction(p1.Y - p2.Y, p1.X - p2.X));
}
static void Main(string[] args)
{
const int limit = 2500000;
mpz_t prime = 2;
int totalCount = 0;
var peaks = new Dictionary <int, Pos>()
{
[0] = new Pos(0, 0, 0),
[1] = new Pos(2, 2, 1)
};
Stopwatch sw = Stopwatch.StartNew();
for (int i = 2; i <= limit; i++)
{
if (i % 10000 == 0)
{
var velocity = (1000000000d) / sw.ElapsedTicks;
Console.Write($"{(double)i / limit:P1}, velocity={velocity:0.00000}\r");
sw.Restart();
}
var next2Primes = (prime = prime.NextPrimeGMP(), prime = prime.NextPrimeGMP());
var xpos = peaks[i - 1].X + next2Primes.Item1 + next2Primes.Item2;
var ypos = peaks[i - 1].Y - next2Primes.Item1 + next2Primes.Item2;
peaks[i] = new Pos(xpos, ypos, i);
}
Console.WriteLine("\nMade peaks");
int lowerLimit = 1;
peaks[2].IsHull = true;
for (int i = 2; ; i++)
{
Console.WriteLine($"{lowerLimit} - {i}, {(double)i / limit:P1}");
int count = 1;
Fraction minAngle = Fraction.AngleBetween(peaks[i], peaks[i - 1]);
for (int j = i - 2; j >= lowerLimit; j--)
{
var angle = Fraction.AngleBetween(peaks[i], peaks[j]);
if (angle.CompareTo(minAngle) < 0)
{
minAngle = angle;
count++;
}
}
totalCount += count;
if (i == limit)
{
break;
}
if (peaks[i].IsHull)
{
var next = peaks.Where(p => p.Key > i)
.OrderByDescending(p => Fraction.AngleBetween(p.Value, peaks[i]))
.First();
next.Value.IsHull = true;
lowerLimit = i;
}
}
Console.WriteLine($"\n{totalCount}");
}
