2nd_Sem_Bogachev/2025.03.21/09Ex/solve.c
2025-03-19 18:57:03 +03:00

50 lines
1.1 KiB
C

#include "solve.h"
#include <math.h>
#define eps 1e-17
int t9_solve(double *a, int m, int n)
{
const int BS = 32;
int max_i = 0, max_j = 0;
double maximum = 0;
for (int jj = 0; jj < n; jj += BS)
for (int ii = 0; ii < m; ii += BS)
for (int j = jj; j < jj + BS && j < n; j++)
for (int i = ii; i < ii + BS && i < m; i++)
{
double sum_i = 0;
double sum_j = 0;
double aij = a[i*n + j];
for (int kk = 0; kk < n; kk += BS)
for (int k = kk; k < kk + BS && k < n; k++) if (k != j)
sum_i += fabs(a[i*n + k] - aij);
for (int kk = 0; kk < m; kk += BS)
for (int k = kk; k < kk + BS && k < m; k++) if (i != k)
sum_j += fabs(a[k*n + j] - aij);
if (((sum_j + sum_i) - maximum) > eps)
maximum = (sum_j + sum_i), max_i = i, max_j = j;
}
for (int l = max_j+1, del_j = 1; l < max_i*n; l++)
{
if (l == ((n * del_j) + max_j))
del_j++;
else
a[l - del_j] = a[l];
}
for (int l = (max_i+1)*n, del_j = max_i; l < m*n; l++)
{
if (l == ((n * (del_j + 1)) + max_j))
del_j++;
else
a[l - del_j - n] = a[l];
}
return max_i * n + max_j;
}