35 lines
1.0 KiB
Rust
35 lines
1.0 KiB
Rust
// leetcode https://leetcode.com/problems/binary-tree-level-order-traversal/
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use super::util::tree::{TreeNode, to_tree};
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use std::collections::VecDeque;
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pub fn level_order(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<Vec<i32>> {
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let mut result: Vec<Vec<i32>> = vec![];
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if root.is_none() { return result; }
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let mut deque: VecDeque<Option<Rc<RefCell<TreeNode>>>> = VecDeque::new();
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deque.push_back(root);
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while !deque.is_empty() {
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let mut current_level = vec![];
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let mut added = false;
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let level_size = deque.len();
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for i in 0..level_size {
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let n = deque.pop_front();
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if let Some(Some(node)) = n {
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current_level.push(node.borrow().val);
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added = true;
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if node.borrow().left.is_some() { deque.push_back(node.borrow().left.clone()); }
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if node.borrow().right.is_some() { deque.push_back(node.borrow().right.clone()); }
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}
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}
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if !added { break; }
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result.push(current_level);
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}
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result
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}
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