20240215 Finished

This commit is contained in:
jackfiled 2024-02-15 11:27:21 +08:00
parent 56df4346f9
commit 1d3664aa57
2 changed files with 82 additions and 1 deletions

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@ -48,3 +48,4 @@ mod p144_binary_tree_preorder_traversal;
mod p145_binary_tree_postorder_traversal;
mod p987_vertical_order_traversal_of_a_binary_tree;
mod p102_binary_tree_level_order_traversal;
mod p107_binary_tree_level_order_traversal_ii;

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@ -0,0 +1,80 @@
/**
* [107] Binary Tree Level Order Traversal II
*/
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;
use std::collections::VecDeque;
impl Solution {
pub fn level_order_bottom(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<Vec<i32>> {
let root = if let Some(r) = root {
r
} else {
return vec![];
};
let mut result = Vec::new();
let mut queue = VecDeque::new();
queue.push_back(root);
while !queue.is_empty() {
let mut level = Vec::with_capacity(queue.len());
for _ in 0..queue.len() {
if let Some(node) = queue.pop_front() {
level.push(node.borrow().val);
if let Some(left) = &node.borrow().left {
queue.push_back(Rc::clone(left));
}
if let Some(right) = &node.borrow().right {
queue.push_back(Rc::clone(right));
}
}
}
result.push(level);
}
result.reverse();
result
}
}
// submission codes end
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_107() {
assert_eq!(Solution::level_order_bottom(
to_tree(vec![Some(3), Some(9), Some(20), None, None, Some(15), Some(7)])
), vec![vec![15, 7], vec![9, 20], vec![3]]);
}
}