20240211 Finished

This commit is contained in:
jackfiled 2024-02-11 13:17:27 +08:00
parent 9cbfc4e1c3
commit 1f1fc6a2d7
2 changed files with 64 additions and 1 deletions

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@ -44,3 +44,4 @@ mod p2641_cousins_in_binary_tree_ii;
mod p993_cousins_in_binary_tree; mod p993_cousins_in_binary_tree;
mod p236_lowest_common_ancestor_of_a_binary_tree; mod p236_lowest_common_ancestor_of_a_binary_tree;
mod p94_binary_tree_inorder_traversal; mod p94_binary_tree_inorder_traversal;
mod p144_binary_tree_preorder_traversal;

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@ -0,0 +1,62 @@
/**
* [144] Binary Tree Preorder Traversal
*/
pub struct Solution {}
use crate::util::tree::{TreeNode, to_tree};
// submission codes start here
// 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;
impl Solution {
pub fn preorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result = Vec::new();
let mut stack = Vec::new();
let mut root = root;
while root.is_some() || !stack.is_empty() {
while let Some(r) = root {
result.push(r.borrow().val);
stack.push(Rc::clone(&r));
root = r.borrow().left.clone();
}
let node = stack.pop().unwrap();
root = node.borrow().right.clone();
}
result
}
}
// submission codes end
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_144() {
assert_eq!(Solution::preorder_traversal(to_tree(
vec![Some(1), None, Some(2), Some(3)])), vec![1,2,3]);
}
}