/*
    Copyright (C) 2009, 2017 William Hart

    This file is part of FLINT.

    FLINT is free software: you can redistribute it and/or modify it under
    the terms of the GNU Lesser General Public License (LGPL) as published
    by the Free Software Foundation; either version 2.1 of the License, or
    (at your option) any later version.  See <https://www.gnu.org/licenses/>.
*/

#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "ulong_extras.h"

int main(void)
{
   int i, result;
   ulong bits, root, hi, n;
   mp_limb_t d;
   FLINT_TEST_INIT(state);
   
   flint_printf("is_perfect_power....");
   fflush(stdout);

   for (i = 0; i < 1000 * flint_test_multiplier(); i++) /* Test that squares pass the test */
   {
      bits = n_randint(state, FLINT_BITS/2) + 1;
      d = n_randtest_bits(state, bits);

      result = n_is_perfect_power(&root, n_pow(d, 2));
      if (result == 0)
      {
         flint_printf("FAIL:\n");
         flint_printf("d^2 = %wu is declared not a perfect power\n", d*d);
         abort();
      }
      if (n_pow(root, result) != n_pow(d, 2))
      {
         flint_printf("FAIL:\n");
         flint_printf("%wu^%wu != %wu\n", root, result, d*d);
         abort();
      }
   }
         
   for (i = 0; i < 1000 * flint_test_multiplier(); i++) /* Test that cubes pass the test */
   {
      bits = n_randint(state, FLINT_BITS/3) + 1;
      d = n_randtest_bits(state, bits);

      result = n_is_perfect_power(&root, n_pow(d, 3));
      if (result == 0)
      {
         flint_printf("FAIL:\n");
         flint_printf("d^3 = %wu is declared not a perfect power\n", d*d*d);
         abort();
      }
      if (n_pow(root, result) != n_pow(d, 3))
      {
         flint_printf("FAIL:\n");
         flint_printf("%wu^%wu != %wu\n", root, result, d*d*d);
         abort();
      }
   }
         
   for (i = 0; i < 1000 * flint_test_multiplier(); i++) /* Test that fifth powers pass the test */
   {
      bits = n_randint(state, FLINT_BITS/5) + 1;
      d = n_randtest_bits(state, bits);

      result = n_is_perfect_power(&root, n_pow(d, 5));
      if (result == 0)
      {
         flint_printf("FAIL:\n");
         flint_printf("d^5 = %wu is declared not a perfect power\n", d*d*d*d*d);
         abort();
      }
      if (n_pow(root, result) != n_pow(d, 5))
      {
         flint_printf("FAIL:\n");
         flint_printf("%wu^%wu != %wu\n", root, result, d*d*d*d*d);
         abort();
      }
   }
         
   /* exhaustively test all other powers */
   for (d = 2; d < (UWORD(1) << (FLINT_BITS/5)); d++)
   {
      hi = 0;
      n = d*d;
      
      while (hi == 0)
      {
         result = n_is_perfect_power(&root, n);
         if (n_pow(root, result) != n)
         {
            flint_printf("FAIL:\n");
            flint_printf("%wu^%wu != %wu\n", root, result, n);
            abort();
         }         

         umul_ppmm(hi, n, n, d);
      }
   }
 
   for (i = 0; i < 10000 * flint_test_multiplier(); i++) /* Test that non perfect powers fail */
   {
      mpz_t d_m;
      mpz_init(d_m);

      do
      {
         d = n_randtest(state);
         flint_mpz_set_ui(d_m, d);
      } while (mpz_perfect_power_p(d_m));

      result = !n_is_perfect_power(&root, d);
      if (!result)
      {
         flint_printf("FAIL:\n");
         flint_printf("d = %wu is declared a perfect power\n", d); 
         abort();
      }

      mpz_clear(d_m);
   }

   FLINT_TEST_CLEANUP(state);
   
   flint_printf("PASS\n");

   return 0;
}