diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/mp.c | 68 | ||||
| -rw-r--r-- | src/mp.h | 3 | ||||
| -rw-r--r-- | src/parserfunc.c | 25 | ||||
| -rw-r--r-- | src/test-mp-equation.c | 5 |
4 files changed, 87 insertions, 14 deletions
@@ -383,7 +383,7 @@ void mp_logarithm(int64_t n, const MPNumber *x, MPNumber *z) { /* log(0) undefined */ - if (mp_is_zero(x)) + if (mp_is_zero(x)) { /* Translators: Error displayed when attempting to take logarithm of zero */ mperr(_("Logarithm of zero is undefined")); @@ -525,19 +525,65 @@ mp_modulus_divide(const MPNumber *x, const MPNumber *y, MPNumber *z) return; } - mp_set_from_mp(x, z); - mp_divide(x, y, z); - mp_floor(z, z); - mp_multiply(z, y, z); - mp_subtract(x, z, z); - MPNumber t1 = mp_new(); + MPNumber t2 = mp_new(); + + mp_divide(x, y, &t1); + mp_floor(&t1, &t1); + mp_multiply(&t1, y, &t2); + mp_subtract(x, &t2, z); + mp_set_from_integer(0, &t1); if ((mp_compare(y, &t1) < 0 && mp_compare(z, &t1) > 0) || (mp_compare(y, &t1) > 0 && mp_compare(z, &t1) < 0)) mp_add(z, y, z); mp_clear(&t1); + mp_clear(&t2); +} + + +void +mp_modular_exponentiation(const MPNumber *x, const MPNumber *y, const MPNumber *p, MPNumber *z) +{ + MPNumber base_value = mp_new(); + MPNumber exp_value = mp_new(); + MPNumber ans = mp_new(); + MPNumber two = mp_new(); + MPNumber tmp = mp_new(); + + mp_set_from_integer(1, &ans); + mp_set_from_integer(2, &two); + mp_abs(y, &exp_value); + + if (mp_is_negative(y)) + mp_reciprocal(x, &base_value); + else + mp_set_from_mp(x, &base_value); + + while (!mp_is_zero(&exp_value)) + { + mp_modulus_divide(&exp_value, &two, &tmp); + + bool is_even = mp_is_zero(&tmp); + if (!is_even) + { + mp_multiply(&ans, &base_value, &ans); + mp_modulus_divide(&ans, p, &ans); + } + mp_multiply(&base_value, &base_value, &base_value); + mp_modulus_divide(&base_value, p, &base_value); + mp_divide_integer(&exp_value, 2, &exp_value); + mp_floor(&exp_value, &exp_value); + } + + mp_modulus_divide(&ans, p, z); + + mp_clear(&base_value); + mp_clear(&exp_value); + mp_clear(&ans); + mp_clear(&two); + mp_clear(&tmp); } @@ -694,7 +740,7 @@ mp_factorize(const MPNumber *x) list = g_list_append(list, factor); factor = g_slice_alloc0(sizeof(MPNumber)); mpc_init2(factor->num, PRECISION); - } + } else { mp_add_integer(&divisor, 2, &tmp); @@ -707,8 +753,8 @@ mp_factorize(const MPNumber *x) { mp_set_from_mp(&value, factor); list = g_list_append(list, factor); - } - else + } + else { mpc_clear(factor->num); g_slice_free(MPNumber, factor); @@ -758,7 +804,7 @@ mp_factorize_unit64(uint64_t n) mp_set_from_unsigned_integer(n, factor); list = g_list_append(list, factor); } - else + else { mpc_clear(factor->num); g_slice_free(MPNumber, factor); @@ -204,6 +204,9 @@ void mp_factorial(const MPNumber *x, MPNumber *z); /* Sets z = x mod y */ void mp_modulus_divide(const MPNumber *x, const MPNumber *y, MPNumber *z); +/* Sets z = x ^ y mod p */ +void mp_modular_exponentiation(const MPNumber *x, const MPNumber *y, const MPNumber *p, MPNumber *z); + /* Sets z = x^y */ void mp_xpowy(const MPNumber *x, const MPNumber *y, MPNumber *z); diff --git a/src/parserfunc.c b/src/parserfunc.c index ff5c6f4..c63ff96 100644 --- a/src/parserfunc.c +++ b/src/parserfunc.c @@ -688,10 +688,29 @@ pf_do_mod(ParseNode* self) mp_free(left); if(right) mp_free(right); - free(ans); + mp_free(ans); return NULL; } - mp_modulus_divide(left, right, ans); + if (self->left->evaluate == pf_do_x_pow_y) + { + MPNumber* base_value = (MPNumber*) (*(self->left->left->evaluate))(self->left->left); + MPNumber* exponent = (MPNumber*) (*(self->left->right->evaluate))(self->left->right); + if(!base_value || !exponent) + { + if(base_value) + mp_free(base_value); + if(exponent) + mp_free(exponent); + mp_free(ans); + return NULL; + } + mp_modular_exponentiation(base_value, exponent, right, ans); + mp_free(base_value); + mp_free(exponent); + } + else + mp_modulus_divide(left, right, ans); + mp_free(left); mp_free(right); return ans; @@ -769,7 +788,7 @@ pf_do_add(ParseNode* self) return ans; } -/*Add (x) Percentage to value. */ +/* Add (x) Percentage to value. */ void* pf_do_add_percent(ParseNode* self) { diff --git a/src/test-mp-equation.c b/src/test-mp-equation.c index c1c136a..c6ab98c 100644 --- a/src/test-mp-equation.c +++ b/src/test-mp-equation.c @@ -482,6 +482,11 @@ test_equations(void) test("8 mod 7", "1", 0); test("−1 mod 7", "6", 0); + test("123^456 mod 78", "27", 0); + test("2^2 mod 2", "0", 0); + test("1^0 mod 2", "1", 0); + test("2^1 mod 1", "0", 0); + test("sgn 0", "0", 0); test("sgn 3", "1", 0); test("sgn −3", "−1", 0); |