rust_btree_rc.rs

use std::cell::RefCell;
use std::rc::Rc;
#[derive(Debug, PartialEq)]
struct Node2 {
    data: i32,
    left: Option<Rc<RefCell<Node2>>>,
    right: Option<Rc<RefCell<Node2>>>,
}
fn add2(tree:&mut Rc<RefCell<Node2>>, x: i32){ 
    let mut u=tree.borrow_mut();
    if u.data==x{
        return;         
    }
    let t=u.data;

    let target_node = if x < t { &mut u.left } else { &mut u.right };
    match  target_node {
        Some(node)=>add2(node, x),
        None=>{
            let new_node=Node2{data:x,left:None,right:None};
            let boxed=Some(Rc::new(RefCell::new(new_node)));
            

            *target_node=boxed;            
        }
    }

}
fn travel2(tree: &Rc<RefCell<Node2>>) {

    let l=&tree.borrow().left;
    if let Some(t)=l{
        travel2(t);
    }
    let d=tree.borrow().data;
    println!("{}",d);
    let r=&tree.borrow().right;
    if let Some(t)=r{
        travel2(t);
    }   
}


fn main() {
    let  node=Node2{data:12,left:None,right:None};
    let mut tree=Rc::new(RefCell::new(node));
    let b=&mut tree;
    add2(b, 200);
    add2(b, 190);
    add2(b, 213);
    add2(b, 56);
    add2(b, 24);
    add2(b, 18);
    add2(b, 27);
    add2(b, 28);
    travel2(&tree);
}