sum-root-to-leaf-numbers/src/main.rs


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// Definition for a binary tree node.
#[derive(Debug, PartialEq, Eq)]
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
    }
  }
}
use std::rc::Rc;
use std::cell::RefCell;

struct Solution;
impl Solution {
    pub fn sum_numbers(root: Option<Rc<RefCell<TreeNode>>>) -> i32 {
        Solution::sum_numbers_before(root, 0)
    }
    pub fn sum_numbers_before(root: Option<Rc<RefCell<TreeNode>>>, before: i32) -> i32 {
        let Some(node) = root else {return 0;};
        let n = &node.borrow();
        let mut sum = 0;
        if n.left.is_some() {sum += Solution::sum_numbers_before(n.left.clone(), before * 10 + n.val);}
        if n.right.is_some() {sum += Solution::sum_numbers_before(n.right.clone(), before * 10 + n.val);}
        sum
    }
}


fn main() {
    println!("Hello, world!");
}