2nd_Sem_Bogachev/2025.04.04/14Ex/solve.c

55 lines
1 KiB
C

#include "solve.h"
#include "io_status.h"
#include <float.h>
// c - changes in rows
int t14_solve(int n, double * restrict A, double * restrict X, int * restrict c)
{
for (int k = 0; k < n; ++k) {
int kn = 0, maxn = 0
max_t max = { .val = -1.0 };
for (int i = k; i < n; ++i)
for (int j = k; j < n; ++j)
{
double aij = fabs(A[i * n + j]);
if (aij > max.val) {
max.val = aij;
max.i = i;
max.j = j;
}
}
if (fabs(max.val) < DBL_EPSILON)
return SINGULAR;
#pragma omp parallel for
for (int j = 0; j < n; ++j)
{
double swap = X[k*n + j];
X[k*n + j] = X[max.i*n + j];
X[max.i*n + j] = swap;
if (j >= k)
{
swap = A[k*n + j];
A[k*n + j] = A[max.i*n + j];
A[max.i*n + j] = swap;
}
}
#pragma omp parallel for
for (int i = 0; i < n; ++i)
{
double swap = X[i*n + k];
X[i*n + k] = X[i*n + max.j];
X[i*n + max.j] = swap;
if (i >= k)
{
swap = A[i*n + k];
A[i*n + k] = A[i*n + max.j];
A[i*n + max.j] = swap;
}
}
}
}