hello-algo/codes/rust/chapter_tree/binary_tree_dfs.rs
rongyi ef3010bd77
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idomatic structure rust code, no include macro (#1528)
2024-10-23 18:49:47 +08:00

71 lines
2.1 KiB
Rust

/*
* File: binary_tree_dfs.rs
* Created Time: 2023-04-06
* Author: xBLACKICEx (xBLACKICE@outlook.com)
*/
use hello_algo_rust::include::{vec_to_tree, TreeNode, print_util};
use hello_algo_rust::op_vec;
use std::cell::RefCell;
use std::rc::Rc;
/* 前序遍历 */
fn pre_order(root: Option<&Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result = vec![];
if let Some(node) = root {
// 访问优先级:根节点 -> 左子树 -> 右子树
result.push(node.borrow().val);
result.extend(pre_order(node.borrow().left.as_ref()));
result.extend(pre_order(node.borrow().right.as_ref()));
}
result
}
/* 中序遍历 */
fn in_order(root: Option<&Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result = vec![];
if let Some(node) = root {
// 访问优先级:左子树 -> 根节点 -> 右子树
result.extend(in_order(node.borrow().left.as_ref()));
result.push(node.borrow().val);
result.extend(in_order(node.borrow().right.as_ref()));
}
result
}
/* 后序遍历 */
fn post_order(root: Option<&Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result = vec![];
if let Some(node) = root {
// 访问优先级:左子树 -> 右子树 -> 根节点
result.extend(post_order(node.borrow().left.as_ref()));
result.extend(post_order(node.borrow().right.as_ref()));
result.push(node.borrow().val);
}
result
}
/* Driver Code */
fn main() {
/* 初始化二叉树 */
// 这里借助了一个从数组直接生成二叉树的函数
let root = vec_to_tree(op_vec![1, 2, 3, 4, 5, 6, 7]);
println!("初始化二叉树\n");
print_util::print_tree(root.as_ref().unwrap());
/* 前序遍历 */
let vec = pre_order(root.as_ref());
println!("\n前序遍历的节点打印序列 = {:?}", vec);
/* 中序遍历 */
let vec = in_order(root.as_ref());
println!("\n中序遍历的节点打印序列 = {:?}", vec);
/* 后序遍历 */
let vec = post_order(root.as_ref());
print!("\n后序遍历的节点打印序列 = {:?}", vec);
}