Thread: Problem in updating global pointer in tree.

Hi, I am having trouble updating my global pointer in the following code,

Code:

#include <iostream>

using namespace std;

struct RB{
    RB()=default;
    RB(int clr):color(clr) { }
    int color;
    RB *p,*left,*right;
    int key;
    
};
RB *Tnil=new RB(0);
RB *T=Tnil;
void insert(RB *T,RB *z)
{
    RB *y=Tnil;
    RB *x=T;
    while(x!=Tnil)
    {
        y=x;
        if(z->key<y->key)
        x=x->left;
        else
        x=x->right;
    }
    z->p=y;
    if(y==Tnil)
        T=z;
    else if(z->key<y->key)
        y->left==z;
    else
        y->right=z;
    z->right=Tnil;
    z->left=Tnil;
    z->color=1;
}
void print(RB *T)
{
    if(T==Tnil)
    return;
    print(T->left);
    cout<<T->key;
    print(T->right);
}

int main()
{
    
  for(int i=1;i<10;++i)
  {
    RB *x=new RB;
    x->key=i;
    insert(T,x);
  
  }
   print(T); 
    
    
}

The problem is, at line where I compar y==Tnil, It is evaluating to false at the first insert. But It should be true. again, after ending the function, T again becomes equal Tnil, as a result , none of the is being inserted. Any help?

thanks... now I understand..