72 lines
2.1 KiB
Rust
72 lines
2.1 KiB
Rust
/*
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* File: binary_tree_dfs.rs
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* Created Time: 2023-04-06
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* Author: xBLACKICEx (xBLACKICE@outlook.com)
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*/
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include!("../include/include.rs");
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use std::cell::RefCell;
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use std::rc::Rc;
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use tree_node::{vec_to_tree, TreeNode};
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/* Pre-order traversal */
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fn pre_order(root: Option<&Rc<RefCell<TreeNode>>>) -> Vec<i32> {
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let mut result = vec![];
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if let Some(node) = root {
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// Visit priority: root node -> left subtree -> right subtree
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result.push(node.borrow().val);
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result.extend(pre_order(node.borrow().left.as_ref()));
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result.extend(pre_order(node.borrow().right.as_ref()));
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}
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result
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}
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/* In-order traversal */
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fn in_order(root: Option<&Rc<RefCell<TreeNode>>>) -> Vec<i32> {
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let mut result = vec![];
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if let Some(node) = root {
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// Visit priority: left subtree -> root node -> right subtree
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result.extend(in_order(node.borrow().left.as_ref()));
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result.push(node.borrow().val);
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result.extend(in_order(node.borrow().right.as_ref()));
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}
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result
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}
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/* Post-order traversal */
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fn post_order(root: Option<&Rc<RefCell<TreeNode>>>) -> Vec<i32> {
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let mut result = vec![];
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if let Some(node) = root {
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// Visit priority: left subtree -> right subtree -> root node
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result.extend(post_order(node.borrow().left.as_ref()));
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result.extend(post_order(node.borrow().right.as_ref()));
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result.push(node.borrow().val);
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}
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result
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}
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/* Driver Code */
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fn main() {
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/* Initialize binary tree */
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// Use a specific function to convert an array into a binary tree
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let root = vec_to_tree(op_vec![1, 2, 3, 4, 5, 6, 7]);
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println!("Initialize binary tree\n");
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print_util::print_tree(root.as_ref().unwrap());
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/* Pre-order traversal */
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let vec = pre_order(root.as_ref());
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println!("\nPrint sequence of nodes in pre-order traversal = {:?}", vec);
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/* In-order traversal */
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let vec = in_order(root.as_ref());
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println!("\nPrint sequence of nodes in in-order traversal = {:?}", vec);
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/* Post-order traversal */
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let vec = post_order(root.as_ref());
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print!("\nPrint sequence of nodes in post-order traversal = {:?}", vec);
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}
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