tree.rs

use rand::Rng;

struct Node {
    v: i32,
    l: Option<Box<Node>>,
    r: Option<Box<Node>>
}

fn make_node(v: i32) -> Node {
    return Node {
        v: v,
        l: None,
        r: None 
    }
}

fn print_order(root: &Node) {
    match &root.l {
        Some(lroot) => {
            print_order(lroot);
        },
        None => {}
    }

    println!("{}", root.v);

    match &root.r {
        Some(rroot) => {
            print_order(rroot);
        },
        None => {}
    }
}

fn add_node(root: &mut Node, v: i32) {
    if v < root.v {
        if let Some(lroot) = &mut root.l {
            add_node(lroot, v);
        } else {
            root.l = Some(Box::new(make_node(v)));
        }
    } else if v > root.v {
        if let Some(rroot) = &mut root.r {
            add_node(rroot,v);
        } else {
            root.r = Some(Box::new(make_node(v)));
        }
    }
}

fn main() {
    let mut rng = rand::thread_rng();
    let mut a: [i32; 100] = [0; 100];

    for x in 0..100 {
        a[x] = rng.gen_range(0..99);
    }

    let mut root = make_node(a[0]);

    for x in 1..100 {
        add_node(&mut root, a[x]);
    }

    print_order(&root);
}