mirror of
https://github.com/boostorg/integer.git
synced 2025-10-31 08:11:37 +01:00
76 lines
2.2 KiB
C++
76 lines
2.2 KiB
C++
|
/*
|
||
|
|
* (C) Copyright Nick Thompson 2018.
|
||
|
|
* Use, modification and distribution are subject to the
|
||
|
|
* Boost Software License, Version 1.0. (See accompanying file
|
||
|
|
* LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define BOOST_TEST_MODULE discrete_log_test
|
||
|
|
#include <boost/test/included/unit_test.hpp>
|
||
|
|
#include <boost/integer/discrete_log.hpp>
|
||
|
|
|
||
|
|
|
||
|
|
using boost::integer::trial_multiplication_discrete_log;
|
||
|
|
using boost::integer::baby_step_giant_step_discrete_log;
|
||
|
|
|
||
|
|
template<class Z>
|
||
|
|
void test_trial_multiplication_discrete_log()
|
||
|
|
{
|
||
|
|
|
||
|
|
boost::optional<Z> x = trial_multiplication_discrete_log<Z>(2, 1, 3);
|
||
|
|
BOOST_CHECK_EQUAL(0, x.value());
|
||
|
|
x = trial_multiplication_discrete_log<Z>(2, 2, 3);
|
||
|
|
BOOST_CHECK_EQUAL(1, x.value());
|
||
|
|
|
||
|
|
x = trial_multiplication_discrete_log<Z>(2, 1, 4);
|
||
|
|
BOOST_CHECK_EQUAL(0, x.value());
|
||
|
|
|
||
|
|
x = trial_multiplication_discrete_log<Z>(2, 2, 4);
|
||
|
|
BOOST_CHECK_EQUAL(1, x.value());
|
||
|
|
|
||
|
|
// No solution to 2^^x mod 4 = 3:
|
||
|
|
x = trial_multiplication_discrete_log<Z>(2, 3, 4);
|
||
|
|
BOOST_TEST(!x);
|
||
|
|
|
||
|
|
x = trial_multiplication_discrete_log<Z>(7, 7, 41);
|
||
|
|
BOOST_CHECK_EQUAL(1, x.value());
|
||
|
|
x = trial_multiplication_discrete_log<Z>(7, 8, 41);
|
||
|
|
BOOST_CHECK_EQUAL(2, x.value());
|
||
|
|
x = trial_multiplication_discrete_log<Z>(7, 15, 41);
|
||
|
|
BOOST_CHECK_EQUAL(3, x.value());
|
||
|
|
x = trial_multiplication_discrete_log<Z>(7, 23, 41);
|
||
|
|
BOOST_CHECK_EQUAL(4, x.value());
|
||
|
|
x = trial_multiplication_discrete_log<Z>(7, 38, 41);
|
||
|
|
BOOST_CHECK_EQUAL(5, x.value());
|
||
|
|
x = trial_multiplication_discrete_log<Z>(7, 20, 41);
|
||
|
|
BOOST_CHECK_EQUAL(6, x.value());
|
||
|
|
|
||
|
|
|
||
|
|
Z k = 1;
|
||
|
|
for (Z i = 0; i < 40; ++i)
|
||
|
|
{
|
||
|
|
x = trial_multiplication_discrete_log<Z>(7, k, 41);
|
||
|
|
BOOST_CHECK_EQUAL(i, x.value());
|
||
|
|
k = (7*k) % 41;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
template<class Z>
|
||
|
|
void test_bsgs_discrete_log()
|
||
|
|
{
|
||
|
|
baby_step_giant_step_discrete_log<Z> dl(7, 41);
|
||
|
|
BOOST_CHECK_EQUAL(dl(7), 1);
|
||
|
|
BOOST_CHECK_EQUAL(dl(8), 2);
|
||
|
|
BOOST_CHECK_EQUAL(dl(15), 3);
|
||
|
|
BOOST_CHECK_EQUAL(dl(23), 4);
|
||
|
|
BOOST_CHECK_EQUAL(dl(38), 5);
|
||
|
|
BOOST_CHECK_EQUAL(dl(20), 6);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
BOOST_AUTO_TEST_CASE(discrete_log_test)
|
||
|
|
{
|
||
|
|
test_trial_multiplication_discrete_log<size_t>();
|
||
|
|
test_bsgs_discrete_log<int>();
|
||
|
|
}
|