C ++中的多维数组

Question

Is there an available implementation of multi-dimensional array in C++ where the number of dimensions are specified at runtime? Basically, I am looking for something like this:

// create a 4 dimensional array 
int num_dim = 4; 
int sizes[4] = {3, 2, 4, 5}; // size for each dimension
MultiArray<int> A( num_dim, sizes ); 

// accessing a element in the array
int index[4] = {2, 2, 1, 0};
A[index] = 3; 

Edit: Notice that I don't want to use either std::vector<std::vector<...>> or boost::multi_array because I do not know the number of dimensions before hand.

Answer 1

Yes the implementation exists in boost

http://www.boost.org/doc/libs/1_55_0/libs/multi_array/doc/user.html

typedef boost::multi_array<double, 3> array_type;
  typedef array_type::index index;
  array_type A(boost::extents[3][4][2]);

Answer 2

Notice that I don't want to use either std::vector<std::vector<...>> or boost::multi_array because I do not know the number of dimensions before hand.

Use of std::vector<std::vector<...>> is most appropriate for your situation.

int m;
int n;

// Read the dimensions of the 2D array.
std::cin >> m >> n;

// Create a 2D array of size m x n using `std::vector`.
std::vector<std::vector<int>> array(m, std::vector<int>(n));