Coderandhacker:

I have written this code for strict Binary Search trees. (If every non-leaf Node in a binary tree has nonempty left and right subtrees, the tree is termed a strictly binary tree. Or, to put it another way, all of the nodes in a strictly binary tree are of degree zero or two, never degree one. A strictly binary tree with N leaves always contains 2N – 1 nodes.) Unfortunately, it's not printing values correctly. I don't know what's the problem. I have seen other sites on the internet and the code is nearly same but still, I can't find a bug in my code.

#include 
#include 
struct node
{
    struct node* prev;
    int data;
    struct node* next;
};
void Binary_Search_Tree(struct node *newnode,struct node *p);
void print(struct node* p);

main()
{
    struct node *root,*nnode,*temp;
    int c,d;
    root=malloc(sizeof(struct node));

    printf("Enter the root data\t");
    scanf("%d",&d);
    root->data=d;
    root->prev=NULL;
    root->next=NULL;

    while(1)
    {
        printf("Enter your choice\n1 insert element.\n2 print tree.\n3 Exit");
        scanf("%d",&c);
        switch(c)
        {
            case 1:
                nnode=malloc(sizeof(struct node));
                printf("Enter the node data\t");
                scanf("%d",&d);

                nnode->data=d;
                nnode->prev=NULL;
                nnode->next=NULL;
                temp=root;

                Binary_Search_Tree(nnode,temp);
                break;
            case 2:
                temp=root;
                print(temp);
                break;
            case 3:
                free(root);
                free(nnode);
                free(temp);
                temp=nnode=root=NULL;
                exit(1);
                break;
        }
    }
    return 0;
}

void Binary_Search_Tree(struct node *newnode,struct node *p)
{

    if(newnode->datadata)
    {
        if(p->prev=NULL)
        {
            p->prev=newnode;
        }
        else if(p->prev!=NULL)
        {
            p=p->prev;
            Binary_Search_Tree(newnode,p);
        }
    }
    else if(newnode->data>p->data)
    {
        if(p->next=NULL)
        {
            p->next=newnode;
        }
        else if(p->next!=NULL)
        {
            p=p->next;
            Binary_Search_Tree(newnode,p);
        }
    }
}

void print(struct node* p)
{
    if(p!=NULL)
    {
        print(p->prev);
        printf("%d\n",p->data);
        print(p->next);
    }
}