leetcode_prelude 0.2.3

use std::cell::RefCell;
use std::rc::Rc;

/// Definition for a binary tree node.
///
/// # Note
///
/// I add Ord PartialOrd for sort Vec<TreeNode> when testing
/// Please don't rely on it
#[derive(Debug, PartialEq, Eq, Ord, PartialOrd)]
pub struct TreeNode {
    pub val: i32,
    pub left: Option<Rc<RefCell<TreeNode>>>,
    pub right: Option<Rc<RefCell<TreeNode>>>,
}

impl TreeNode {
    #[inline]
    pub fn new(val: i32) -> Self {
        TreeNode {
            val,
            left: None,
            right: None,
        }
    }
}

/// Create a binary tree with TreeNode
///
/// # Example
///
/// ```rust
/// use leetcode_prelude::btree;
///
/// let tree = btree![1, 2, 3, null, null, 4, 5];
/// ```
#[macro_export]
macro_rules! btree {
    () => {
        None
    };
    ($($e:expr), *) => {
        {
            use std::rc::Rc;
            use std::cell::RefCell;

            let elems = vec![$(stringify!($e)), *];
            let elems = elems.iter().map(|n| n.parse::<i32>().ok()).collect::<Vec<_>>();
            let head = Some(Rc::new(RefCell::new($crate::TreeNode::new(elems[0].unwrap()))));
            let mut nodes = std::collections::VecDeque::new();
            nodes.push_back(head.as_ref().unwrap().clone());

            for i in elems[1..].chunks(2) {
                let node = nodes.pop_front().unwrap();
                if let Some(val) = i[0]{
                    node.borrow_mut().left = Some(Rc::new(RefCell::new($crate::TreeNode::new(val))));
                    nodes.push_back(node.borrow().left.as_ref().unwrap().clone());
                }
                if i.len() > 1 {
                    if let Some(val) = i[1] {
                        node.borrow_mut().right = Some(Rc::new(RefCell::new($crate::TreeNode::new(val))));
                        nodes.push_back(node.borrow().right.as_ref().unwrap().clone());
                    }
                }
            }
            head
        }
    };
}

#[cfg(test)]
mod tests {

    #[test]
    fn test() {
        let btree = btree![-1, 2, 3, null];
        println!("{:#?}", btree);
    }
}