C++ : Unhandled exception at 0x00101890 in xxx: 0xC0000005: Access violation reading location 0xcccccccc

Question

I have meet a problem that i cant debug my code. it keep showing me that unhandled exception.

#include <iostream>
#include <stdlib.h>
#include <ctime>

#define max 10

using namespace std;


struct Node{
    int data;
    Node *next;
};

void initNode(Node *tmpHead, int n){
    tmpHead->data =n;
    tmpHead->next =NULL;
}

void displayNodes(Node *cur) {
    cout <<"Data is";
    while(cur){
        cout<< cur -> data << " ";
        cur = cur->next;
    }
    cout << " *\n" <<endl;
}

void addNodes(Node * cur, int n){
    Node *newNode = new Node;
    newNode-> data = n;
    newNode-> next = NULL;

    while( cur -> next){
        cur = cur -> next;
    }
    cur -> next = newNode;
}

int countTotalNodes(Node *cur){
    int count =0;
    while(cur){
        count++;
        cur = cur->next;
    }
    return count;
}





void  main () {
    srand(time(NULL));

    Node* head = new Node;
    int i =0;
    int j= 0;
    initNode ( head, rand() %100); 


    for ( int i = 0; i<max-1; i++)
        addNodes( head, rand() % 100);

    cout << endl;
    cout << "Entered array is: " << endl;
    displayNodes( head); 

    Node* array[max];
    Node* cur= head;
    Node* k;
    for( int j = 0; j<max ; j++) 
    {
        array[i] = cur;
        cur = cur->next;
    }
    for (int i=0; i<max-1; i++) //sorting 
    {
        for(int j=0; j<max-i-1; j++)
        {
            if(array[j]->data > array[j+1]->data)
            {
                k = array[j];
                array[j] = array [j+1];
                array[j+1] = k;
            }
        }
    }
    head = array[0];
    for (int i =0; i<max -1; i++)
        array[i]->next = array[i+1];
    array[max-1]->next = NULL;

    cout <<"Sorted Array is: " <<endl;
    displayNodes( head);


}

I have found the part which i cant run it

if(array[j]->data > array[j+1]->data)

i tried to retype it and it still giving me the same error. tried a few different pc it giving me the same error or it crashed.

Answer 1

Your code says:

for( int j = 0; j<max ; j++) 
{
    array[i] = cur;
    cur = cur->next;
}

But using i as the index to the array makes no sense because j is the loop variable so the array contains random pointers because it isn't initialized properly.

You should run you code in a debugger like I just did and step through the program and watch what it does - it makes finding these things much easier.