DR 6.2 Binary tree to linked list Whole code

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

struct node2
{
    void* data;
    struct node2* one;
    struct node2* two;
};

struct node1 {
    void* data;
    struct node1* next;
};


void prnint(void* p)
{
    printf("%d ", *(int*)p);
}

struct node2* newNode(int data)
{
    void* p = malloc(sizeof(data));
    *(int*)p = data;
    struct node2* t = (struct node2*)malloc(sizeof(struct node2));
    t->data = p;
    t->one = NULL;
    t->two = NULL;
    return t;
}

void printList(struct node2* p)
{
    //printf("\n");
    static struct node2* root;
    if (root == NULL)
        root = p;
    while (p != NULL)
    {
        prnint(p->data);
        p = p->two;
        if (p == root) // Възлите на цикъла започват да се повтарят
            break;
    }
}



void display(struct node1** head)
{
    struct node1* t = *head;
    do {
        prnint(t->data);
        t = t->next;
    } while (t != *head);
}

void add1(void* data, struct node1** head)
{
    struct node1* p = *head;
    if (p == NULL)
    {
        p = (struct node1*)malloc(sizeof(struct node1));
        p->data = data;
        p->next = NULL;
        *head = p;
        return;
    }
    else
    {
        while (p->next)
            p = p->next;
        struct node1* t = (struct node1*)malloc(sizeof(struct node1));
        t->data = data;
        t->next = NULL;
        p->next = t;
    }
}

//void add2(void* data, struct node1** head)
//{
//  struct node1* p = (struct node1*)malloc(sizeof(struct node1));
//  p->data = data;
//  if (head != NULL)
//      p->next = *head;
//  else
//      p->next = NULL;
//  *head = p;
//}

void preorder(struct node2* p, struct node1** listHead)
{
    if (!p)
        return;
    add1(p->data, listHead);
    preorder(p->one, listHead);
    preorder(p->two, listHead);
}

void postorder(struct node2* p, struct node1** listHead)
{
    if (!p)
        return;
    postorder(p->one, listHead);
    postorder(p->two, listHead);
    add1(p->data, listHead);
}


void postorderPrint(struct node2* p)
{
    if (!p)
        return;
    postorderPrint(p->one);
    postorderPrint(p->two);
    prnint(p->data);

}
void preorderPrint(struct node2* p)
{
    if (!p)
        return;
    prnint(p->data);
    preorderPrint(p->one);
    preorderPrint(p->two);
}


void postorderFUN(struct node2* p, struct node1** listHead)
{
    postorder(p, listHead);
    struct node1* t = *listHead;
    while (t->next != NULL)
        t = t->next;
    t->next = *listHead;
    putchar('\n');
}


void preorderFUN(struct node2* p, struct node1** listHead)
{
    preorder(p, listHead);
    struct node1* t = *listHead;
    while (t->next != NULL)
        t = t->next;
    t->next = *listHead;
    putchar('\n');
}




int main()
{
    struct node1* listHead = NULL;

    struct node2* root = newNode(2);
    root->one = newNode(4);
    root->two = newNode(19);
    root->one->one = newNode(7);
    root->one->two = newNode(10);
    root->two->one = newNode(22);
    /*
     *          2
     *        /   \
     *       4     19
     *      / \   /
     *     7  10 22
     */
    postorderPrint(root);
    postorderFUN(root, &listHead);
    display(&listHead);
    listHead = NULL;
    preorderPrint(root);
    preorderFUN(root, &listHead);
    display(&listHead);
}