You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
hello-algo/zh-hant/codes/rust/chapter_tree/binary_tree_dfs.rs

72 lines
2.0 KiB

/*
* File: binary_tree_dfs.rs
* Created Time: 2023-04-06
* Author: xBLACKICEx (xBLACKICE@outlook.com)
*/
include!("../include/include.rs");
use std::cell::RefCell;
use std::rc::Rc;
use tree_node::{vec_to_tree, TreeNode};
/* 前序走訪 */
fn pre_order(root: Option<&Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result = vec![];
if let Some(node) = root {
// 訪問優先順序:根節點 -> 左子樹 -> 右子樹
result.push(node.borrow().val);
result.extend(pre_order(node.borrow().left.as_ref()));
result.extend(pre_order(node.borrow().right.as_ref()));
}
result
}
/* 中序走訪 */
fn in_order(root: Option<&Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result = vec![];
if let Some(node) = root {
// 訪問優先順序:左子樹 -> 根節點 -> 右子樹
result.extend(in_order(node.borrow().left.as_ref()));
result.push(node.borrow().val);
result.extend(in_order(node.borrow().right.as_ref()));
}
result
}
/* 後序走訪 */
fn post_order(root: Option<&Rc<RefCell<TreeNode>>>) -> Vec<i32> {
let mut result = vec![];
if let Some(node) = root {
// 訪問優先順序:左子樹 -> 右子樹 -> 根節點
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() {
/* 初始化二元樹 */
// 這裡藉助了一個從陣列直接生成二元樹的函式
let root = vec_to_tree(op_vec![1, 2, 3, 4, 5, 6, 7]);
println!("初始化二元樹\n");
print_util::print_tree(root.as_ref().unwrap());
/* 前序走訪 */
let vec = pre_order(root.as_ref());
println!("\n前序走訪的節點列印序列 = {:?}", vec);
/* 中序走訪 */
let vec = in_order(root.as_ref());
println!("\n中序走訪的節點列印序列 = {:?}", vec);
/* 後序走訪 */
let vec = post_order(root.as_ref());
print!("\n後序走訪的節點列印序列 = {:?}", vec);
}