Algorithms/algo
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

feat(geektime_algo): 23 binary tree split inorder, preorder and

Browse Source 
postorder traversal
This commit is contained in:
Caitlin Gao 2019-07-23 07:11:38 +08:00
parent 192a137904
commit 6154a44c84
4 changed files with 136 additions and 61 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
rust/23_binary_tree/binary_tree_traversal.rs
View File

@ -1,61 +0,0 @@
use super::util::tree::{TreeNode, to_tree};
// 前序遍历
pub fn pre_order_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result: Vec<i32> = vec![];
if root.is_none() { return result; }
_pre_order(root, &mut result);
result
}
fn _pre_order(root: Option<Rc<RefCell<TreeNode>>>, result: &mut Vec<i32>) {
match root {
Some(node) => {
result.push(node.borrow().val);
_pre_order(node.borrow().left.clone(), result);
_pre_order(node.borrow().right.clone(), result);
},
None => { return; }
}
}
// 中序遍历
pub fn in_order_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result: Vec<i32> = vec![];
if root.is_none() { return result; }
_in_order(root, &mut result);
result
}
fn _in_order(root: Option<Rc<RefCell<TreeNode>>>, result: &mut Vec<i32>) {
match root {
Some(node) => {
_in_order(node.borrow().left.clone(), result);
result.push(node.borrow().val);
_in_order(node.borrow().right.clone(), result);
},
None => { return; }
}
}
// 后续遍历
pub fn post_order_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result: Vec<i32> = vec![];
if root.is_none() { return result; }
_post_order(root, &mut result);
result
}
fn _post_order(root: Option<Rc<RefCell<TreeNode>>>, result: &mut Vec<i32>) {
match root {
Some(node) => {
_post_order(node.borrow().left.clone(), result);
_post_order(node.borrow().right.clone(), result);
result.push(node.borrow().val);
},
None => { return; }
}
}

44
rust/23_binary_tree/inorder_traversal.rs Normal file
View File

@ -0,0 +1,44 @@
// leetcode: https://leetcode.com/problems/binary-tree-inorder-traversal/
use super::util::tree::{TreeNode, to_tree};
// 中序遍历（Recursive Approach）
pub fn inorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result: Vec<i32> = vec![];
if root.is_none() { return result; }
_inorder(root, &mut result);
result
}
fn _inorder(root: Option<Rc<RefCell<TreeNode>>>, result: &mut Vec<i32>) {
match root {
Some(node) => {
_inorder(node.borrow().left.clone(), result);
result.push(node.borrow().val);
_inorder(node.borrow().right.clone(), result);
},
None => { return; }
}
}
// 中序遍历（Iterating method using Stack）
pub fn inorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result = vec![];
if root.is_none() { return result; }
let mut stack: Vec<Rc<RefCell<TreeNode>>> = Vec::new();
let mut r = root.clone();
while r.is_some() || !stack.is_empty() {
while let Some(node) = r {
stack.push(node.clone());
r = node.borrow().left.clone();
}
r = stack.pop();
if let Some(node) = r {
result.push(node.borrow().val);
r = node.borrow().right.clone();
}
}
result
}

48
rust/23_binary_tree/postorder_traversal.rs Normal file
View File

@ -0,0 +1,48 @@
// https://leetcode.com/problems/binary-tree-postorder-traversal/
use super::util::tree::{TreeNode, to_tree};
// 后续遍历（Recursive Approach）
pub fn postorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result: Vec<i32> = vec![];
if root.is_none() { return result; }
_postorder(root, &mut result);
result
}
fn _postorder(root: Option<Rc<RefCell<TreeNode>>>, result: &mut Vec<i32>) {
match root {
Some(node) => {
_postorder(node.borrow().left.clone(), result);
_postorder(node.borrow().right.clone(), result);
result.push(node.borrow().val);
},
None => { return; }
}
}
// 后序遍历（Iterating method using Stack）
pub fn postorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result = vec![];
if root.is_none() { return result; }
let mut stack1: Vec<Option<Rc<RefCell<TreeNode>>>> = Vec::new();
let mut stack2: Vec<Option<Rc<RefCell<TreeNode>>>> = Vec::new();
stack1.push(root);
while let Some(Some(node)) = stack1.pop() {
if node.borrow().left.is_some() {
stack1.push(node.borrow().left.clone());
}
if node.borrow().right.is_some() {
stack1.push(node.borrow().right.clone());
}
stack2.push(Some(node));
}
while let Some(Some(node)) = stack2.pop() {
result.push(node.borrow().val);
}
result
}

44
rust/23_binary_tree/preorder_traversal.rs Normal file
View File

@ -0,0 +1,44 @@
//leetcode: https://leetcode.com/problems/binary-tree-preorder-traversal/
use super::util::tree::{TreeNode, to_tree};
// 前序遍历（Recursive Approach）
pub fn preorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result: Vec<i32> = vec![];
if root.is_none() { return result; }
_preorder(root, &mut result);
result
}
fn _preorder(root: Option<Rc<RefCell<TreeNode>>>, result: &mut Vec<i32>) {
match root {
Some(node) => {
result.push(node.borrow().val);
_preorder(node.borrow().left.clone(), result);
_preorder(node.borrow().right.clone(), result);
},
None => { return; }
}
}
// 前序遍历（Iterating method using Stack）
pub fn inorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result = vec![];
if root.is_none() { return result; }
let mut stack: Vec<Rc<RefCell<TreeNode>>> = Vec::new();
let mut r = root.clone();
while r.is_some() || !stack.is_empty() {
while let Some(node) = r {
result.push(node.borrow().val);
stack.push(node.clone());
r = node.borrow().left.clone();
}
r = stack.pop();
if let Some(node) = r {
r = node.borrow().right.clone();
}
}
result
}