primetest3.frink

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// Exhaustive and inefficient test to check isPrime, but one that
// doesn't require memory proportional to the largest number checked.

a = eval[input["Start from [2]: ", 2]]

highest = 2^31 - 1;

for n = a to highest
{
   if n % 50000 == 0 // Print progress every 50000 digits
      print["$n\t"]
   
   if isPrimeByDivision[n] != isPrime[n]  // Test against internal routine
      println["Error!  $n"];
}


// Function to exhaustively test if a number is prime by trial division.
// It checks all intergers up to the square root of the number to
// be tested.
isPrimeByDivision[n] :=
{
   for i = 2 to floor[sqrt[n]]
   {
      if (n mod i == 0)
         return false
   }

   return true
}
      


Download or view primetest3.frink in plain text format

This is a program written in the programming language Frink.
For more information, view the Frink Documentation or see More Sample Frink Programs.

Alan Eliasen, eliasen@mindspring.com