prime.cpp

   1 //-----------------------------------------------------------------------------
   2 //
   3 //      Look up the nth prime
   4 //
   5 //      Input:          n on stack (0 < n < 10001)
   6 //
   7 //      Output:         nth prime on stack
   8 //
   9 //-----------------------------------------------------------------------------
  10
  11 #include "stdafx.h"
  12 #include "defs.h"
  13
  14 void
  15 eval_prime(void)
  16 {
  17         push(cadr(p1));
  18         eval();
  19         prime();
  20 }
  21
  22 void
  23 prime(void)
  24 {
  25         int n;
  26         n = pop_integer();
  27         if (n < 1 || n > MAXPRIMETAB)
  28                 stop("prime: Argument out of range.");
  29         n = primetab[n - 1];
  30         push_integer(n);
  31 }