|
| 1 | +/* |
| 2 | + * [0019] binary-tree-inorder-traversal |
| 3 | + */ |
| 4 | + |
| 5 | +pub struct Solution {} |
| 6 | +use super::utils::tree::TreeNode; |
| 7 | + |
| 8 | +// solution impl starts here |
| 9 | + |
| 10 | +// Definition for a binary tree node. |
| 11 | +// #[derive(Debug, PartialEq, Eq)] |
| 12 | +// pub struct TreeNode { |
| 13 | +// pub val: i32, |
| 14 | +// pub left: Option<Rc<RefCell<TreeNode>>>, |
| 15 | +// pub right: Option<Rc<RefCell<TreeNode>>>, |
| 16 | +// } |
| 17 | +// |
| 18 | +// impl TreeNode { |
| 19 | +// #[inline] |
| 20 | +// pub fn new(val: i32) -> Self { |
| 21 | +// TreeNode { |
| 22 | +// val, |
| 23 | +// left: None, |
| 24 | +// right: None |
| 25 | +// } |
| 26 | +// } |
| 27 | +// } |
| 28 | +use std::cell::RefCell; |
| 29 | +use std::rc::Rc; |
| 30 | +impl Solution { |
| 31 | + pub fn inorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> { |
| 32 | + let mut res: Vec<i32> = Vec::new(); |
| 33 | + let mut curr = root.clone(); |
| 34 | + |
| 35 | + while let Some(cur) = curr.clone() { |
| 36 | + let cur = cur.borrow(); |
| 37 | + if cur.left.is_some() { |
| 38 | + let mut pre = cur.left.clone().unwrap(); |
| 39 | + while pre.borrow().right.is_some() && pre.borrow().right != curr { |
| 40 | + let a = pre.borrow().right.clone().unwrap(); |
| 41 | + pre = a; |
| 42 | + } |
| 43 | + if pre.borrow().right.is_none() { |
| 44 | + pre.borrow_mut().right = curr; |
| 45 | + curr = cur.left.clone(); |
| 46 | + } |
| 47 | + if pre.borrow().right == curr { |
| 48 | + pre.borrow_mut().right = Option::None; |
| 49 | + res.push(cur.val); |
| 50 | + curr = cur.right.clone(); |
| 51 | + } |
| 52 | + } else { |
| 53 | + res.push(cur.val); |
| 54 | + curr = cur.right.clone(); |
| 55 | + } |
| 56 | + } |
| 57 | + |
| 58 | + res |
| 59 | + } |
| 60 | +} |
| 61 | +// solution impl ends here |
| 62 | + |
| 63 | +// solution tests starts here |
| 64 | + |
| 65 | +#[cfg(test)] |
| 66 | +mod tests { |
| 67 | + use super::*; |
| 68 | + |
| 69 | + #[test] |
| 70 | + fn test_case0() { |
| 71 | + assert_eq!( |
| 72 | + Solution::inorder_traversal(tree![1, null, 2, 3]), |
| 73 | + vec![1, 3, 2] |
| 74 | + ); |
| 75 | + } |
| 76 | +} |
| 77 | + |
| 78 | +// solution tests ends here |
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