allocation

How would I go about dynamically allocating a multi-dimensional array? If you know the size of nested dimensions already, you can also literally allocate a multi dimensional array using new: typedef int dimensions[3][4]; dimensions * dim = new dimensions[10]; dim[/* from 0 to 9 */][/* from 0 to 2 */][/* from 0 to 3 */] = 42; delete [] dim; instead of 10 , a runtime determined value can be passed. Since it's not part of the type operator new returns, that's allowed. This is nice if you know the number of columns, but want to keep the number of rows variable, for example. The typedef makes it

Under a 32-bit operating system, where maximum memory allocated to any one program is limited, Mathematica gracefully terminates the kernel and returns a max memory allocation error. On a 64-bit OS however, Mathematica will freely use all the memory available and grind the system to a halt. Therefore, what is the correct way to cap memory usage? One could use MemoryConstrained combined with $Pre or CellEvaluationFunction but I would rather not tie up either of those for this purpose, or have to modify existing uses to incorporate this function. Is there another way to globally restrict memory

In a project, somebody pushed this line: double (*e)[n+1] = malloc((n+1) * sizeof(*e)); Which supposedly creates a two-dimensional array of (n+1)*(n+1) doubles. Supposedly , I say, because so far, nobody I asked could tell me what this does, exactly, nor where it originated from or why it should work (which allegedly, it does, but I'm not yet buying it). Perhaps I'm missing something obvious, but I'd appreciate it if somebody could explain above line to me. Because personally, I'd feel much better if we'd use something we actually understand. The variable e is a pointer to an array of n + 1

Possible Duplicate: what’s the point in malloc(0)? Why does malloc(0) actually return a valid pointer for writing ? char *str = NULL; str = (char*)malloc(0); // allocate 0 bytes ? printf("Pointer of str: %p\n", str); strcpy(str, "A very long string ..................."); printf("Value of str: %s", str); free(str); // Causes crash if str is too long Output: Pointer of str: 0xa9d010 Aborted Value of str: A very long string ................... When str is shorter then it just works as it should. BTW: For compiling I used GCC with "-D_FORTIY_SOURCE=0 -fno-stack-protector" *** glibc detected *** ..

Hi I'm pretty new to C++ and I need to dynamicacally allocate two-dimensional array. No error but in runtime when I set a order and first row then I get a runtime error: "Segmentation Fault"...Here's code: #include <iostream> using namespace std; double ** allocateDynamicArray(int &order){ double ** arr = new double *[order]; for(int i = 0;i < order; i++){ *arr = new double[order+1]; } return arr; } void deallocateDynamicArray(double **arr, int order){ for(int i=0; i<order; i++){ delete [] arr[i]; } delete [] arr; } void addAndPrintArray(double **arr, int order){ cout << "Zadejte prvky pole