Thread: xor linked list

okay i got the insert function working, i got the delete function working correctly, but i am having problems with the list function...here is what my program looks like with just dumby variables as the data and not rndm()!!

Code:

#include <stdio.h>
#include <stdlib.h>

#define MAX_NUMBERS 100

typedef struct _node{
        int data;
        unsigned long link;
} node;//end node

node *head, *tail;

void  insert(int insertNum){

        node *nekw, *tmp, *next, *prv, *cur;
        nekw = malloc(sizeof(node));
        cur = head;
        prv = NULL;
        nekw->data = insertNum;

        if(cur == NULL){
                head = nekw;
                cur = head;
                next = tail;
        }//end if statement.

        else if(cur->data > nekw->data){
                tmp = cur;
                cur = nekw;
                cur->link = tmp->link;
                next = (node*)(cur->link ^ (unsigned long)prv);
                if(next == NULL){
                        next = tmp;
                        tail = next;
                }//end if statement
                else{
                        tmp->link = (unsigned long)cur ^ (unsigned long)next;
                        cur->link = (unsigned long)prv ^ (unsigned long)tmp;
                        nekw = (node *)(next->link ^ (unsigned long) cur);
                        next->link = (unsigned long)nekw ^ (unsigned long)tmp;
                        cur = tmp;
                }//end else statement
        }//end else if statement
        else{
                while((cur != NULL) && (cur->data < nekw->data)){
                        next = (node *)(cur->link ^ (unsigned long)prv);
                        prv = cur;
                        cur = next;
                }//end while loop
                if(next == NULL){
                        cur = nekw;
                        tail = cur;
                }//end if statement
                else{
                        nekw->link = (unsigned long) cur ^(unsigned long) next;
                        cur->link = (unsigned long) nekw ^ (unsigned long) prv;
                        tmp = (node *)(next->link ^ (unsigned long)cur);
                        next->link = (unsigned long) nekw ^ (unsigned long) tmp;
                        cur = nekw;
                }//end else
        }//end else statement
}//end insert.

void delete(int deleteNum){
        node *cur, *prv, *next;
        cur = head;
        prv = NULL;
        while(cur != NULL && (cur->data != deleteNum)){
                prv =(node *)(cur->link ^ (unsigned long)next);
                prv = cur;
                cur = next;
        }//end while loop
        if(cur != NULL && (cur->data == deleteNum)){
                prv->link = (unsigned long) prv ^ (unsigned long) cur;
                next->link = (unsigned long) cur^ (unsigned long) next;
                free(cur);
        }//end if statement.
}//end delete.

 void list(){ //int option
        int cnt;
        node *cur, *prv, *next, *tmp;
        tmp = malloc(sizeof(node));
        cur = head; //here is where i have a breakpoint for gdb!!!
        prv = NULL;
        printf("This is the list in acending order: \n");
        while(cnt < MAX_NUMBERS){
                   printf("&#37;d", cur->data);
                   cnt++;
                   next = (node *)(cur->link ^ (unsigned long)prv);
                   prv = cur;
                   cur = next;
                   printf("  %d", cur->data);//this is where it will error because cur = NULL
                   if(cnt % 10 == 0){
                             printf("\n");
                   }//end if statement.
        }//end while loop

}//end list.

int main(){
        head = NULL;
        tail = head;
        static int cnt, numDelete;

        for(cnt=1; cnt < MAX_NUMBERS; cnt++){
                insert(cnt);
        }//end for loop.

        list();

        numDelete = 99;
        delete(numDelete);

        list();

        return 0;
}//end main.