2D Malloc

Daniel has been working on his COMP1511 assignment, but he wants to create a 2D rows x cols array of integers, where rows and cols are inputs to the program.

In other words, he wants to create some array int array[rows][cols].

Unfortunately, the style guide for the course does not allow variable length arrays to be created on the stack, so Daniel must malloc his array. Of course, this also means he has to free all memory afterwards!

Daniel does not know how to dynamically allocate heap memory for a 2D array and free it afterwards, so your job is to implement the functions allocate_array and free_array in malloc_two_dimension_array.c.

• int **allocate_array(int rows, int cols) should take in two values, rows and cols, and should return the start of a heap-allocated array with bounds and behaviour which matches int array[rows][cols].
• void free_array(int **array, int rows, int cols) should take in three values — array is the start of the array to be freed, rows and cols are the dimensions of the array.

The main function has already been included. This main function reads rows and cols as command line arguments, passes it to allocate_array, does some array operations, and then calls free_array. Do not modify this function, you may create new functions if you wish.

The output should look exactly like the following:

$ dcc --leak-check 2d_malloc.c -o 2d_malloc
$ ./2d_malloc 10 10
   0    1    2    3    4    5    6    7    8    9
  10   11   12   13   14   15   16   17   18   19
  20   21   22   23   24   25   26   27   28   29
  30   31   32   33   34   35   36   37   38   39
  40   41   42   43   44   45   46   47   48   49
  50   51   52   53   54   55   56   57   58   59
  60   61   62   63   64   65   66   67   68   69
  70   71   72   73   74   75   76   77   78   79
  80   81   82   83   84   85   86   87   88   89
  90   91   92   93   94   95   96   97   98   99

Assumptions/Restrictions/Clarifications

• You may assume there is enough memory to allocate the array on the heap.
• You may not store the arrays on the stack.
• You do not need to worry about a horrific eldritch abomination destroying your computer midway through runtime.

CSE Autotest

When you think your program is working, you can use CSE autotest to test your solution.

$ 1511 csesoc-autotest 2d_malloc

Solution

You can view the solution code to this problem here.