C++ Binary Search Tree Implementation - c++

Question

I am working on a project in C++ in which I have to create a binary search tree that inserts items from an array. I have to use the following insert algorithm:
tree-insert(T, z)
y = NIL
x = T.root
while x != NIL
y = x
if z.key < x.key
x = x.left
else x = x.right
z.p = y
if y == NIL
T.root = z
else if z.key < y.key
y.left = z
else y.right = z
Here is what I have so far:
#include <iostream>
using namespace std;
struct node
{
int key;
node* left;
node* right;
node* p;
node* root;
};
void insert(node*, node*);
void printinorder(node*);
int main()
{
node *root;
node* tree = new node;
node* z = new node;
int array [10] = {30, 10, 45, 38, 20, 50, 25, 33, 8, 12};
for (int i = 0; i < 10; i++)
{
z->key = array[i];
insert(tree, z);
}
printinorder(tree);
return 0;
}
void insert(node *T, node *z)
{
node *y = nullptr;
node* x = new node;
x = T->root;
while (x != NULL)
{
y = x;
if (z->key < x->key)
x = x->left;
else
x = x->right;
}
z->p = y;
if (y == NULL)
T->root = z;
else if (z->key < y->key)
y->left = z;
else
y->right = z;
}
void printinorder(node *x)
{
if (x != NULL)
{
printinorder(x->left);
cout << x->key << endl;
printinorder(x->right);
}
}
This code compiles however when I run it, it seg faults. I believe the problem has something to do with the nodes I am creating or my function calls.
Thanks for your help.

Answer 1

Besides the issues noted in the comments, the biggest bug in this code is a lack of a constructor that initializes all pointers in a new node to NULL.
As such, every node you create will have its pointers containing random garbage. You code initializes some of them, but most are not. Trying to use uninitialized pointers will result in an immediate crash.
You need to fix all the problems that have been noted in the comments, and have a proper constructor for your node class.