2nd_Sem_Bogachev/2025.04.04/dist/Ulyanov_MT/task20.c
2025-04-13 19:02:35 +03:00

176 lines
4.6 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#include "io_status.h"
#include "array.h"
#include "matrix.h"
io_status inverse(double*, double*, int*, int);
int main(int argc, char* argv[])
{
io_status res;
int task = 20;
double* a;
double* b;
int* ind;
int n, p, k;
char* name = 0;
double r1, r2;
double t;
if (!((argc == 4 || argc == 5) && sscanf(argv[1], "%d", &n) == 1 && sscanf(argv[2], "%d", &p) == 1 && sscanf(argv[3], "%d", &k) == 1 && k >= 0 && k <= 4))
{
printf("Usage: %s n p k [file]\n", argv[0]);
return 1;
}
if (k == 0) name = argv[4];
a = (double*) malloc(n * n * sizeof(double));
if (!a)
{
printf("Not enough memory\n");
return 2;
}
if (name)
{
io_status ret;
ret = read_matrix(a, n, n, name);
if (ret != SUCCESS)
{
switch(ret)
{
case ERROR_OPEN:
printf("Can not open file %s\n", name);
break;
case ERROR_READ:
printf("Can not read file %s\n", name);
break;
default:
printf("Unknown error %d in file %s\n", ret, name);
}
free(a);
return 3;
}
}
else
init_matrix(a, n, n, k);
b = (double*) malloc(n * n * sizeof(double));
if (!b)
{
printf("Not enough memory\n");
free(a);
return 2;
}
init_idmatrix(b, n);
ind = (int*) malloc(n * sizeof(int));
if (!ind)
{
printf("Not enough memory\n");
free(a);
free(b);
return 2;
}
init_ind(ind, n);
printf("Matrix:\n");
print_matrix(a, n, n, p);
t = clock();
res = inverse(a, b, ind, n);
t = (clock() - t) / CLOCKS_PER_SEC;
if (res == ERROR_MATRIX)
{
printf("Method is not applicable or inverse matrix does not exist\n");
free(a);
free(b);
free(ind);
return 0;
}
if (name) read_matrix(a, n, n, name);
else init_matrix(a, n, n, k);
r1 = count_r1(a, b, n);
r2 = count_r2(a, b, n);
printf("Inverse matrix:\n");
print_matrix(b, n, n, p);
printf ("%s : Task = %d Res1 = %e Res2 = %e Elapsed = %.2f K = %d N = %d\n", argv[0], task, r1, r2, t, k, n);
free(a);
free(b);
free(ind);
return 0;
}
io_status inverse(double* a, double* b, int* ind, int n)
{
int tmp, i, j, k, ind_max_i, ind_max_j;
double bag, mod_el_a, el_aik, el_akk, max, norm;
norm = count_norm(a, n);
for (k = 0; k < n; k++)
{
max = 0;
ind_max_i = k;
ind_max_j = k;
for (i = k; i < n; i++)
{
for (j = k; j < n; j++)
{
mod_el_a = fabs(a[i * n + j]);
if (mod_el_a > max)
{
max = mod_el_a;
ind_max_i = i;
ind_max_j = j;
}
}
}
for (j = k; j < n; j++)
{
bag = a[k * n + j];
a[k * n + j] = a[ind_max_i * n + j];
a[ind_max_i * n + j] = bag;
}
for (j = 0; j < n; j++)
{
bag = b[k * n + j];
b[k * n + j] = b[ind_max_i * n + j];
b[ind_max_i * n + j] = bag;
}
for (i = 0; i < n; i++)
{
bag = a[i * n + k];
a[i * n + k] = a[i * n + ind_max_j];
a[i * n + ind_max_j] = bag;
}
tmp = ind[k];
ind[k] = ind[ind_max_j];
ind[ind_max_j] = tmp;
el_akk = a[k * n + k];
if (is_null(el_akk, norm)) return ERROR_MATRIX;
for (j = k + 1; j < n; j++) a[k * n + j] = a[k * n + j] / el_akk;
for (j = 0; j < n; j++) b[k * n + j] = b[k * n + j] / el_akk;
for (i = 0; i < n; i++)
{
if (i != k)
{
el_aik = a[i * n + k];
for (j = k + 1; j < n; j++) a[i * n + j] = a[i * n + j] - el_aik * a[k * n + j];
for (j = 0; j < n; j++) b[i * n + j] = b[i * n + j] - el_aik * b[k * n + j];
}
}
}
tmp = -1;
for (i = 0; i < n; i++)
{
while (i != tmp)
{
tmp = ind[i];
for (j = 0; j < n; j++)
{
bag = b[tmp * n + j];
b[tmp * n + j] = b[i * n + j];
b[i * n + j] = bag;
}
ind[i] = ind[tmp];
ind[tmp] = tmp;
}
}
return SUCCESS;
}