static IntSet getRow(int row)
{
IntSet newIntset = new IntSet(board[row]);
newIntset.Excl(0);
return(newIntset);
}
public static void Main(string [] args)
{
const int Max = 32000;
IntSet uncrossed = new IntSet(Max); // the sieve //bool[] uncrossed = new bool[Max];
int i, n, k, it, iterations, primes = 0; // counters
IO.Write("How many iterations? ");
iterations = IO.ReadInt();
bool display = iterations == 1;
IO.Write("Supply largest number to be tested ");
n = IO.ReadInt();
if (n > Max)
{
IO.Write("n too large, sorry");
System.Environment.Exit(1);
}
IO.WriteLine("Prime numbers between 2 and " + n);
IO.WriteLine("-----------------------------------");
for (it = 1; it <= iterations; it++)
{
primes = 0;
for (i = 2; i <= n; i++) // clear sieve
{
uncrossed.Incl(i); //uncrossed[k] = true;
}
for (i = 2; i <= n; i++) // the passes over the sieve
{
if (uncrossed.Contains(i)) //uncrossed[i]
{
if (display && primes % 8 == 0) // ensure line not too long
{
IO.WriteLine();
}
primes++;
if (display)
{
IO.Write(i, 6);
}
k = i; // now cross out multiples of i
do
{
uncrossed.Excl(k); //uncrossed[k] = false;
k += i;
} while (k <= n);
}
}
if (display)
{
IO.WriteLine();
}
}
IO.Write(primes + " primes");
} // main
public static void Main(string[] args)
{
const int Max = 32000;
IntSet uncrossed = new IntSet(Max);
int i, limit, k, it, iterations, primes = 0; // counters
IO.Write("How many iterations? ");
iterations = IO.ReadInt();
bool display = true;
IO.Write("Supply largest number to be tested ");
limit = IO.ReadInt();
if (limit > Max)
{
IO.Write("limit too large, sorry");
System.Environment.Exit(1);
}
for (it = 1; it <= iterations; it++)
{
primes = 0;
for (i = 2; i <= limit; i++)
{
// clear sieve
uncrossed.Incl(i);
}
for (i = 2; i <= limit; i++)
{ // the passes over the sieve
if (uncrossed.Contains(i) == true)
{
primes++;
k = i; // now cross out multiples of i
do
{
uncrossed.Excl(k);
k += i;
} while (k <= limit);
}
}
}
uncrossed.Incl(1);
IntSet primeSet = new IntSet(uncrossed);
IO.WriteLine("here");
for (i = 2; i <= limit; i++) // clear sieve
{
uncrossed.Incl(i);
}
for (i = 3; i <= limit; i += 2) // exclude reference to odd integers
{
uncrossed.Excl(i);
}
for (i = 4; i <= limit; i += 2)
{ // the passes over the sieve in even numbers greater than 4
if (uncrossed.Contains(i) == true)
{
for (int a = 1; a <= limit; a++)
{
for (int b = 1; b <= limit; b++)
{
if (primeSet.Contains(a) && primeSet.Contains(b))
{
IO.WriteLine(a);
IO.WriteLine(b);
IO.WriteLine(i);
if (a + b == i)
{
IO.WriteLine("N = A + B: -> " + i.ToString() + " = " + a.ToString() + " + " + b.ToString());
}
}
}
}
}
if (display)
{
IO.WriteLine();
}
} // main
}
