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I would like to find out safe ways of implementing three dimensional arrays of integers in C++, using pointer arithmetic / dynamic memory allocation, or, alternatively using STL techniques such as vectors.
Essentially I want my integer array dimensions to look like:
[ x ][ y ][ z ]
x and y are in the range 20-6000 z is known and equals 4.
764
You can think the array as a table with 3 rows and each row has 4 columns. Similarly, you can declare a three-dimensional (3d) array. For example, float y[2][4][3];
A three-dimensional (3D) array is an array of arrays of arrays. In C programming an array can have two, three, or even ten or more dimensions. The maximum dimensions a C program can have depends on which compiler is being used.
A multi-dimensional array is an array with more than one level or dimension. For example, a 2D array, or two-dimensional array, is an array of arrays, meaning it is a matrix of rows and columns (think of a table). A 3D array adds another dimension, turning it into an array of arrays of arrays.
Creating Multidimensional Arrays You can create a multidimensional array by creating a 2-D matrix first, and then extending it. For example, first define a 3-by-3 matrix as the first page in a 3-D array. Now add a second page. To do this, assign another 3-by-3 matrix to the index value 2 in the third dimension.
Have a look at the Boost multi-dimensional array library. Here's an example (adapted from the Boost documentation):
#include "boost/multi_array.hpp"
int main() {
// Create a 3D array that is 20 x 30 x 4
int x = 20;
int y = 30;
int z = 4;
typedef boost::multi_array<int, 3> array_type;
typedef array_type::index index;
array_type my_array(boost::extents[x][y][z]);
// Assign values to the elements
int values = 0;
for (index i = 0; i != x; ++i) {
for (index j = 0; j != y; ++j) {
for (index k = 0; k != z; ++k) {
my_array[i][j][k] = values++;
}
}
}
}
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