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Fix the issue of discuss comment 7919887 (#996)

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易春风
2023-12-23 23:20:26 +08:00
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parent 46813a5247
commit b115a2b895
1 changed files with 101 additions and 118 deletions
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131
codes/rust/chapter_tree/binary_search_tree.rs
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@ -1,73 +1,51 @@
/*
* File: binary_search_tree.rs
* Created Time: 2023-04-20
* Author: xBLACKICEx (xBLACKICE@outlook.com)
* Author: xBLACKICEx (xBLACKICE@outlook.com)、night-cruise (2586447362@qq.com)
*/
include!("../include/include.rs");
use std::{cell::RefCell, rc::Rc};
use std::cell::RefCell;
use std::rc::Rc;
use std::cmp::Ordering;
use tree_node::TreeNode;
type TreeNodeRc = Rc<RefCell<TreeNode>>;
type OptionTreeNodeRc = Option<Rc<RefCell<TreeNode>>>;
/* 二叉搜索树 */
pub struct BinarySearchTree {
root: Option<TreeNodeRc>,
root: OptionTreeNodeRc,
}
impl BinarySearchTree {
/* 构造方法 */
pub fn new(mut nums: Vec<i32>) -> Self {
// 排序数组
nums.sort();
// 构建二叉搜索树
if nums.is_empty() {
pub fn new() -> Self {
// 初始化空树
Self { root: None }
} else {
Self { root: Some(Self::build_tree(&nums)) }
}
}
/* 获取二叉树根节点 */
pub fn get_root(&self) -> Option<TreeNodeRc> {
self.root.clone() // RC 克隆
}
/* 构建二叉搜索树 */
fn build_tree(num: &[i32]) -> TreeNodeRc {
// 将数组中间节点作为根节点
let mid = num.len() / 2;
let root = TreeNode::new(num[mid]);
// 递归建立左子树和右子树
if mid > 0 {
root.borrow_mut().left = Some(Self::build_tree(&num[..mid]));
}
if mid < num.len() - 1 {
root.borrow_mut().right = Some(Self::build_tree(&num[mid + 1..]));
}
root
pub fn get_root(&self) -> OptionTreeNodeRc {
self.root.clone()
}
/* 查找节点 */
pub fn search(&self, num: i32) -> Option<TreeNodeRc> {
pub fn search(&self, num: i32) -> OptionTreeNodeRc {
let mut cur = self.root.clone();
// 循环查找，越过叶节点后跳出
while let Some(node) = cur.clone() {
match num.cmp(&node.borrow().val) {
// 目标节点在 cur 的右子树中
if node.borrow().val < num {
cur = node.borrow().right.clone();
}
Ordering::Greater => cur = node.borrow().right.clone(),
// 目标节点在 cur 的左子树中
else if node.borrow().val > num {
cur = node.borrow().left.clone();
}
Ordering::Less => cur = node.borrow().left.clone(),
// 找到目标节点，跳出循环
else {
break;
Ordering::Equal => break,
}
}
// 返回目标节点
cur
}
@ -83,27 +61,28 @@ impl BinarySearchTree {
let mut pre = None;
// 循环查找，越过叶节点后跳出
while let Some(node) = cur.clone() {
match num.cmp(&node.borrow().val) {
// 找到重复节点，直接返回
if node.borrow().val == num {
return;
}
Ordering::Equal => return,
// 插入位置在 cur 的右子树中
Ordering::Greater => {
pre = cur.clone();
if node.borrow().val < num {
cur = node.borrow().right.clone();
}
// 插入位置在 cur 的左子树中
else {
Ordering::Less => {
pre = cur.clone();
cur = node.borrow().left.clone();
}
}
}
// 插入节点
let node = TreeNode::new(num);
let pre = pre.unwrap();
if pre.borrow().val < num {
pre.borrow_mut().right = Some(Rc::clone(&node));
let node = Some(TreeNode::new(num));
if num > pre.borrow().val {
pre.borrow_mut().right = node;
} else {
pre.borrow_mut().left = Some(Rc::clone(&node));
pre.borrow_mut().left = node;
}
}
@ -117,34 +96,37 @@ impl BinarySearchTree {
let mut pre = None;
// 循环查找，越过叶节点后跳出
while let Some(node) = cur.clone() {
match num.cmp(&node.borrow().val) {
// 找到待删除节点，跳出循环
if node.borrow().val == num {
break;
}
Ordering::Equal => break,
// 待删除节点在 cur 的右子树中
Ordering::Greater => {
pre = cur.clone();
if node.borrow().val < num {
cur = node.borrow().right.clone();
}
// 待删除节点在 cur 的左子树中
else {
Ordering::Less => {
pre = cur.clone();
cur = node.borrow().left.clone();
}
}
}
// 若无待删除节点，则直接返回
if cur.is_none() {
return;
}
let cur = cur.unwrap();
let (left_child, right_child) = (cur.borrow().left.clone(), cur.borrow().right.clone());
match (left_child.clone(), right_child.clone()) {
// 子节点数量 = 0 or 1
if cur.borrow().left.is_none() || cur.borrow().right.is_none() {
(None, None) | (Some(_), None) | (None, Some(_)) => {
// 当子节点数量 = 0 / 1 时， child = nullptr / 该子节点
let child = cur.borrow().left.clone().or_else(|| cur.borrow().right.clone());
let child = left_child.or(right_child);
let pre = pre.unwrap();
let left = pre.borrow().left.clone().unwrap();
// 删除节点 cur
if !Rc::ptr_eq(&cur, self.root.as_ref().unwrap()) {
if Rc::ptr_eq(&left, &cur) {
let left = pre.borrow().left.clone();
if left.is_some() && Rc::ptr_eq(&left.as_ref().unwrap(), &cur) {
pre.borrow_mut().left = child;
} else {
pre.borrow_mut().right = child;
@ -155,7 +137,7 @@ impl BinarySearchTree {
}
}
// 子节点数量 = 2
else {
(Some(_), Some(_)) => {
// 获取中序遍历中 cur 的下一个节点
let mut tmp = cur.borrow().right.clone();
while let Some(node) = tmp.clone() {
@ -173,36 +155,37 @@ impl BinarySearchTree {
}
}
}
}
/* Driver Code */
fn main() {
/* 初始化二叉搜索树 */
let nums = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
let mut bst = BinarySearchTree::new(nums);
println!("初始化的二叉树为\n");
print_util::print_tree(&bst.get_root().unwrap());
let mut bst = BinarySearchTree::new();
// 请注意，不同的插入顺序会生成不同的二叉树，该序列可以生成一个完美二叉树
let nums = [8, 4, 12, 2, 6, 10, 14, 1, 3, 5, 7, 9, 11, 13, 15];
for &num in &nums {
bst.insert(num);
}
println!("\n初始化的二叉树为\n");
print_util::print_tree(bst.get_root().as_ref().unwrap());
/* 查找节点 */
let node = bst.search(7).unwrap();
println!(
"\n查找到的节点对象为: {:p} 节点值 = {}\n",
node.as_ref().as_ptr(),
node.borrow().val
);
/* 查找结点 */
let node = bst.search(7);
println!("\n查找到的节点对象为 {:?}，节点值 = {}", node.clone().unwrap(), node.clone().unwrap().borrow().val);
/* 插入节点 */
bst.insert(16);
println!("插入节点 16 后，二叉树为\n");
print_util::print_tree(&bst.get_root().unwrap());
println!("\n插入节点 16 后，二叉树为\n");
print_util::print_tree(bst.get_root().as_ref().unwrap());
/* 删除节点 */
bst.remove(1);
println!("\n删除节点 1 后，二叉树为\n");
print_util::print_tree(&bst.get_root().unwrap());
print_util::print_tree(bst.get_root().as_ref().unwrap());
bst.remove(2);
println!("\n删除节点 2 后，二叉树为\n");
print_util::print_tree(&bst.get_root().unwrap());
print_util::print_tree(bst.get_root().as_ref().unwrap());
bst.remove(4);
println!("\n删除节点 4 后，二叉树为\n");
print_util::print_tree(&bst.get_root().unwrap());
print_util::print_tree(bst.get_root().as_ref().unwrap());
}