Dynamic Allocation of Structures

[kng]

So i guess the titles says it all i m trying to create dynamic structure of adjacency lists and i m having some errors since i m a little new in C anyone mind taking a look at it and tell me of any mistakes i might be doing

STRUCTURES

struct adjList                       //Data structure for an adjacency List
{
    int pageNo;                     //stores the page number (unique)
    int * link;                     //Stores a list of links to other pages
    int noLinks;                    //No of links stored - If noLinks > 0 then node is a non-dangling node
    // else if noLinks == 0 then its a dangling node
};

struct matrixList                   //Data structure for a Matrix
{
    struct adjList ** matrix;       //Array containing all the rows in our matrix
    int noRows;                     //Total Number of rows in our matrix
    int noColumns;                  //The total number of columns in our matrix
};

struct blockMatrix
{
    struct matrixList  *** block;       //A2 dimensional Array of MatrixList
    int noRows;                      //Total Number of rows in our matrix
    int noColumns;                  //The total number of columns in our matrix
};

// BlockLoading.cpp : main project file.

#include "stdafx.h"
#include "PageRankFuncs.h"
#define _CRTDBG_MAP_ALLOC
#include <stdlib.h>
#include <crtdbg.h>

using namespace System;

int main(array<System::String ^> ^args)
{
    Console::WriteLine(L"Hello World");
    
    _CrtSetDbgFlag ( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF );
    
    blockMatrix * blocks = (blockMatrix *)malloc( sizeof(blockMatrix) );

    //Create a 2 dimesional array of matrices
    blocks->block = (matrixList ***)malloc( sizeof(matrixList **) );
    
    blocks->noColumns = 5;
    blocks->noRows=2;


    for (int y = 0; y < blocks->noColumns; y++ )
    {
       
        blocks->block[y]  = (matrixList **)malloc(sizeof(matrixList));
        
        for ( int x = 0; x < blocks->noRows; x++)
        {
           
            blocks->block[y][x] = (matrixList *)malloc(sizeof(matrixList));
            
            blocks->block[y][x]->matrix = (adjList **)malloc(BLOCK_SIZE * sizeof(adjList));

            for (int z = 0; z < BLOCK_SIZE ; z++ )
            {
                blocks->block[y][x]->matrix[z] = (adjList *) malloc(sizeof(adjList));
                blocks->block[y][x]->matrix[z]->link = (int *)malloc( sizeof(int) );
                blocks->block[y][x]->matrix[z]->link[0] = 22;
            }
        }
    }

   
   
   
   for (int y = 0; y < blocks->noColumns; y++ )
   {

        for ( int x = 0; x < blocks->noRows; x++)
        {

            for (int z = 0; z < BLOCK_SIZE ; z++ )
            {
                
                if ( blocks->block[y][x]->matrix[z]->link != NULL )
                    free( blocks->block[y][x]->matrix[z]->link );
                    
                if ( blocks->block[y][x]->matrix[z] != NULL )
                    free( blocks->block[y][x]->matrix[z] );
            }
            
            if ( blocks->block[y][x]->matrix != NULL )
                free( blocks->block[y][x]->matrix );

            if ( blocks->block[y][x] != NULL )
                free( blocks->block[y][x] );
        }
        
        if ( blocks->block[y] != NULL )
            free( blocks->block[y] );
    }

    if ( blocks->block != NULL )
       free( blocks->block );
        
    if (blocks != NULL)
        free( blocks);
    
    return 0;

}

[kng]

Didn't mention that i am getting an error from line

if ( blocks->block != NULL )
free( blocks->block );

HEAP CORRUPTION DETECTED: after Normal block (#184) at 0x0027A110.
CRT detected that the application wrote to memory after end of heap buffer.

Memory allocated at .\BlockLoading.cpp(20).

[Aia]

Consider this as a friendly warning. You will be ignore by those that can really help you if you don't use the proper C code tags when you post code.
Example here.

[kng]

Thanks Fixxed it should be nice and readable now :D New to the forum BTW

[Salem]

> int main(array<System::String ^> ^args)
What's this crud?
This isn't C.
It isn't even C++.
It's microsoft's munged to hell managed c++, or whatever they call it.

You need to decide which language you're actually using.
Because this "pick any random syntax which seems to compile" approach will lead you into trouble.

blocks->noColumns = 5;
    blocks->noRows=2;
    blocks->block = (matrixList ***)malloc( sizeof(matrixList **) * blocks->noColumns );

    for (int y = 0; y < blocks->noColumns; y++ )
    {
        blocks->block[y]  = (matrixList **)malloc(sizeof(matrixList));

If you're going to treat a block of memory as an array, you need to allocate 'N' of them (and not just one of each).

Ditto for all the other nested 'arrays' you're allocating.

[kng]

Salem First of all i d like to thank you for the timely and accurate reply which worked out :D

Secondly would you mind to take a couple of minutes to explain a little further what is wrong with my code that is the mesh up between c and c++ since i am quite unaware of this

If your talking about

using namespace System;

int main(array<System::String ^> ^args)
{
    Console::WriteLine(L"Hello World");

That has been automatically generated by visual c++ and i was to lazy to translate it into C :P since the application is just a test app to check that my structures are valid.

P.S Thanks Again deeply appretiated

[Salem]

Yeah, there's quite a lot of stuff in the way of writing clean C programs in the newer visceral studio's.

There are several things you need to do.
1. Start with an empty file, and make sure you name it like prog.c

2. Declare main in one of these forms
http://sourceforge.net/apps/mediawiki/cpwiki/index.php?title=Implicit_main

3. In the project->settings->compiler (or there-abouts), locate an option called "pre-compiled headers". Turn it OFF.