Thread: Segmentation Fault-Binary Search Tree

Code:

#include<iostream> 
#include<string> 
using namespace std; 
class node 
{ 
private: 
    int data; 
    node *left; 
    node *right; 
public: 
    node(int d) 
    { 
        data=d; 
        cout<<data<<endl; 
        left=NULL; 
        right=NULL; 
    } 
    friend class list; 
}; 
class list 
{ 
    public: 
        node *root; 
        node *newnode; 
        list() 
        { 
          root=NULL; 
        } 
        void insert(node *r, int data) 
        { 
             
            if(r==NULL) 
            { 
                r=new node(data); 
            } 
            else if(data>r->data) 
            { 
                insert(r->right,data); 
            } 
            else if(data<r->data) 
            { 
                insert(r->left,data); 
            } 
        } 
        /*void insert(node *nd,int data) 
        { 
                if(nd==NULL) 
            { 
                nd=new node(data); 
            } 
            else if(data>nd->data) 
            { 
                insert(nd->right,data); 
            } 
            else if(data<nd->data) 
            { 
                insert(nd->left,data); 
            } 
        }*/ 
        void display(node *temp) 
        { 
            cout<<"sdff"<<endl; 
            cout<<temp->data; 
            if(temp) 
            { 
                cout<<"dsfs"<<temp->data<<endl; 
                display(temp->left); 
                display(temp->right);     
                 
            } 
             
        } 
 
        void display() 
        { 
             
            if(root) 
            { 
                cout<<root->data<<endl; 
                display(root->right); 
                display(root->left); 
                     
                 
            } 
             
        } 
         
}; 
int main() 
{ 
    list l; 
    l.insert(l.root,9); 
    l.insert(l.root,6); 
    l.insert(l.root,10); 
     
    l.display(l.root); 
     
}

what is wrong with my code??