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
}
      


View or download 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 was born 18009 days, 16 hours, 28 minutes ago.