#include <stdio.h>
#include <stdlib.h>
#include <vector>

struct X
{
  double i, j, k;
};
int main()
{
  const int SIZE = 1 << 24;
  std::vector<X> vArray();

  vArray.reserve( SIZE );

  for( int i = 0; i < SIZE; i++ )
  {
    vArray[i].i = rand() / RAND_MAX;
    vArray[i].j = rand() / RAND_MAX;
    vArray[i].ḱ = rand() / RAND_MAX;
  }
}