#define ROW 4
#define COL 4

int main(void)
{
  const double _U[ROW][COL] = {{2, 4, 2, 8}, {3, 5, 2, 7}, {3, 12, 9, 13}, {2, 1, 8, 5}};
  const double _W[ROW][COL] = {{1, 3, 6, 3}, {7, 8, 8, 10}, {5, 3, 14, 2}, {3, 3, 11, 2}};
  double _x[ROW] = {1, 2, 3, 4};
  double _ws[COL] = {0, 0, 0, 0};

  double **U = malloc(ROW * sizeof(double *));
  double **W = malloc(ROW * sizeof(double *));
  for (int i = 0; i < ROW + 1; i++)
  {
    U[i] = malloc(COL * sizeof(double));
    W[i] = malloc(COL * sizeof(double));
  }
  double *x = malloc(COL * sizeof(double));
  double *ws = malloc(COL * sizeof(double));
  for (size_t i = 0; i < ROW; i++)
  {
    x[i] = _x[i];
    ws[i] = _ws[i];
    for (size_t j = 0; j < COL; j++)
    {
      U[i][j] = _U[i][j];
      W[i][j] = _W[i][j];
    }
  }

  strmv(ROW, COL, 0.5, U, W, x, ws);
  printf("|");
  for (size_t i = 0; i < 4; i++)
  {
    printf("\t%.2f\t|", x[i]);
  }
  printf("\n");
}