2nd_Sem_Bogachev/2025.05.02/dist/Krivoruchenko_SK/solve.c
2025-05-11 15:17:22 +03:00

473 lines
6.8 KiB
C

#include "solve.h"
#include "comp.h"
#include "polynom.h"
#include <math.h>
#include <float.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
int t1_solve (
double (*f) (double),
double a, double b,
double eps, int m, double *x
) {
int it = 0;
uint64_t bits;
double c = DBL_MAX, y, y_a = f(a), y_b = f(b);
bool sgn_a, sgn_b, sgn_c;
memcpy(&bits, &y_a, sizeof(bits));
sgn_a = (bits >> 63) & 1;
memcpy(&bits, &y_b, sizeof(bits));
sgn_b = (bits >> 63) & 1;
if (fabs(y_a) - eps < DBL_EPSILON)
{
*x = a;
return 1;
} if (fabs(y_b) - eps < DBL_EPSILON)
{
*x = b;
return 1;
}
if (sgn_a == sgn_b)
{
*x = DBL_MAX;
return -1;
}
for (it = 1; it <= m; ++it)
{
c = (a + b) * 0.5;
y = f(c);
memcpy(&bits, &y, sizeof(bits));
sgn_c = (bits >> 63) & 1;
if (fabs(y) - eps < DBL_EPSILON)
break;
else if ((fabs(c - a) < DBL_EPSILON) || (fabs(c - b) < DBL_EPSILON))
it = m+1;
else if (sgn_c == sgn_a)
{
a = c;
y_a = y;
} else if (sgn_c == sgn_b)
{
b = c;
y_b = y;
}
}
if (it > m)
it = -1;
*x = c;
return it;
}
int t2_solve (
double (*f) (double),
double (*d) (double),
double x_0, double eps,
int m, double *x
) {
int it = 0;
for (it = 1; it <= m; ++it)
{
double y = f(x_0);
double dy = d(x_0);
if (fabs(y) - eps < DBL_EPSILON)
break;
if (fabs(dy) < DBL_EPSILON)
{
it = -1;
break;
}
x_0 -= (y / dy);
}
if (it > m)
it = -1;
*x = x_0;
return it;
}
int t3_solve (
double (*f) (double),
double a, double b,
double eps, int m, double *x
) {
int it = 0;
uint64_t bits;
double c = DBL_MAX, y, y_a = f(a), y_b = f(b);
bool sgn_a, sgn_b, sgn_c;
memcpy(&bits, &y_a, sizeof(bits));
sgn_a = (bits >> 63) & 1;
memcpy(&bits, &y_b, sizeof(bits));
sgn_b = (bits >> 63) & 1;
if (is_eps(y_a, eps))
{
*x = a;
return 1;
} else if (is_eps(y_b, eps))
{
*x = b;
return 1;
}
if (sgn_a == sgn_b)
{
*x = DBL_MAX;
return -1;
}
for (it = 1; it <= m; ++it)
{
c = a - ((b - a) / (y_b - y_a)) * y_a;
y = f(c);
memcpy(&bits, &y, sizeof(bits));
sgn_c = (bits >> 63) & 1;
if (is_eps(y, eps))
break;
else if (sgn_c == sgn_a)
{
a = c;
y_a = y;
} else if (sgn_c == sgn_b)
{
b = c;
y_b = y;
}
}
if (it > m)
it = -1;
*x = c;
return it;
}
int t4_solve (
double (*f) (double),
double a, double b,
double eps, int m, double *x
) {
int it = 0;
double c = DBL_MAX, y, y_a = f(a), y_b = f(b);
if (is_eps(y_a, eps))
{
*x = a;
return 1;
} if (is_eps(y_b, eps))
{
*x = b;
return 1;
} if (is_equal(fabs(y_b), fabs(y_a)))
{
*x = a;
return -1;
}
for (it = 1; it <= m; ++it)
{
// c = b - ((b - a) / (y_b - y_a)) * y_b;
c = a - ((b - a) / (y_b - y_a)) * y_a;
y = f(c);
if (is_eps(y, eps))
break;
else if (fabs(y_a) - fabs(y_b) > DBL_EPSILON)
{
a = c;
y_a = y;
} else
{
b = c;
y_b = y;
}
if (is_equal(y_a, y_b))
it = m+1;
}
if (it > m)
it = -1;
*x = c;
return it;
}
int t5_solve (
double (*f) (double),
double a, double b,
double eps, int m, double *x
) {
int it;
double c = (a + b) * 0.5;
double y_a = f(a);
double y_c = f(c);
double y_b = f(b);
if (is_null(y_a))
{
*x = a;
return 1;
} else if (is_null(y_b))
{
*x = b;
return 1;
} else if (is_null(y_c))
{
*x = c;
return 1;
}
if (is_equal(a, b))
return -1;
else if (is_equal(a, c))
return -1;
else if (is_equal(b, c))
return -1;
for (it = 1; it < m+1; ++it)
{
double *temp_pnt = 0, *inner_max_pnt;
const double angle = (c - a) / (y_c - y_a);
const double x_new = a -
angle * y_a +
((((b - c) / (y_b - y_c)) - angle) / (y_b - y_a)) * y_a * y_c;
const double y_new = f(x_new);
if (is_eps(y_new, eps))
{
*x = x_new;
return it;
}
if (
is_equal(x_new, a) ||
is_equal(x_new, c) ||
is_equal(x_new, b)
)
return -1;
inner_max_pnt = fp_abs_max(&c, &b, &y_c, &y_b, &temp_pnt);
*fp_abs_max(&a, inner_max_pnt, &y_a, temp_pnt, &temp_pnt) = x_new;
*temp_pnt = y_new;
}
if (it > m)
return -2;
else
{
double temp = 0, *temp_x_pnt = fpmax(&c, &b, -y_c, -y_b, &temp);
*x = *fpmax(&a, temp_x_pnt, -y_a, temp, &temp);
return it;
}
}
int t6_solve (
double (*f) (double),
const int m, double *d,
double a, double b,
const double eps, const int M, double *res
) {
const int len = m + 1;
double *y_lst = d;
double *x_lst = d + len;
double *t_lst = d + (len << 1);
int it;
if (is_eps(y_lst[0], eps)) {
*res = a;
return 1;
} else if (is_eps(y_lst[m], eps)) {
*res = b;
return 1;
}
for (it = 1; it <= M; ++it)
{
double maximum = 0;
int max_i = 0;
double x = construct_poly(0, len, y_lst, x_lst);
double y = f(x);
if (is_eps(y, eps))
{
*res = x;
return it;
}
// Возвращение значений функции в x_lst можно было встроить в суммирование полинома, но мало толку
for (int i = 0; i < len; ++i)
{
double xi = t_lst[i];
double yi = y_lst[i];
x_lst[i] = xi;
if (is_equal(y, yi))
return -1;
if ((yi - maximum) > DBL_EPSILON) {
maximum = yi;
max_i = i;
}
}
y_lst[max_i] = y;
x_lst[max_i] = x;
t_lst[max_i] = x;
}
return -1;
}
int t7_solve (
double (*f) (double),
double x_0, double eps,
int m, double *x
) {
int it = 0;
double y = f(x_0);
if (fabs(y - x_0) - eps < DBL_EPSILON)
{
*x = x_0;
return 1;
}
for (it = 1; it <= m; ++it)
{
x_0 = y;
y = f(x_0);
if (fabs(y - x_0) - eps < DBL_EPSILON)
break;
}
if (it > m)
it = -1;
*x = x_0;
return it;
}
int t8_solve (
double (*f) (double),
double a, double b,
double eps, int m, double *res
) {
int it = 1;
double h = a - b;
double x_l = 0, y_l = 0, x = a, y = f(a);
if (fabs(b - a) < DBL_EPSILON)
{
*res = a;
return 1;
}
while (it <= m)
{
h *= -0.1;
while (1)
{
it++;
if (it > m)
return -1;
x_l = x;
y_l = y;
x += h;
y = f(x);
if ((y_l - y) > DBL_EPSILON)
break;
if ((a - x) > DBL_EPSILON || (x - b) > DBL_EPSILON) {
*res = x_l;
return it;
}
}
if ((y_l - y) < eps) {
*res = x_l;
return it;
}
}
return -1;
}
int t9_solve (
double (*f) (double),
double a, double b,
double eps, int m, double *x
) {
const double gdrt = 2 / (1 + sqrt(5));
int it = 0;
double x_1 = b + (a - b) * gdrt, x_2 = a + (b - a) * gdrt;
double y_1 = f(x_1), y_2 = f(x_2);
for (it = 1; it <= m; ++it)
{
if (y_1 - y_2 > DBL_EPSILON)
{
b = x_2;
x_2 = x_1;
y_2 = y_1;
x_1 = b + (a - b) * gdrt;
y_1 = f(x_1);
} else
{
a = x_1;
x_1 = x_2;
y_1 = y_2;
x_2 = a + (b - a) * gdrt;
y_2 = f(x_2);
}
if (fabs(b - a) < eps)
{
*x = x_1;
break;
}
}
if (it > m)
it = -1;
return it;
}