Program in C for XOR list example

Write a program in C for XOR list example

#include <stdio.h>

#include <conio.h>

struct xnode

{

          int data;

          unsigned long direction;

};

struct xnode *add_data(int data, struct xnode* list);

void walk_list(struct xnode *list);

int main(void)

{

          struct xnode *l2 = add_data(2, NULL);

          struct xnode *l1 = add_data(1, l2);

          struct xnode *l3 = add_data(3, l2);

          struct xnode *l4 = add_data(4, l3);

          printf("front -> back....\n");

          walk_list(l1);

          printf("back -> front....\n");

          walk_list(l4);

          return 0;

}

struct xnode *add_data(int data, struct xnode *list)

{

          struct xnode *newxnode = malloc(sizeof(struct xnode));

          assert(newxnode);

          newxnode->direction = (unsigned long)list;

          newxnode->data = data;

          if(list != NULL)

                   list->direction ^= (unsigned long)newxnode;

          return newxnode;

}

void walk_list(struct xnode *list)

{

          unsigned long prev = 0;

          while(list != NULL)

          {

                   unsigned long next = prev ^ list->direction;

                   printf("%d ", list->data);

                   prev = (unsigned long)list;

                   list = (struct xnode *)next;

          }

          printf("\n");

}