hello-algo/en/codes/rust/chapter_tree/binary_tree_bfs.rs

46 lines
1.3 KiB
Rust

/*
* File: binary_tree_bfs.rs
* Created Time: 2023-04-07
* Author: xBLACKICEx (xBLACKICE@outlook.com)
*/
include!("../include/include.rs");
use std::collections::VecDeque;
use std::{cell::RefCell, rc::Rc};
use tree_node::{vec_to_tree, TreeNode};
/* Level-order traversal */
fn level_order(root: &Rc<RefCell<TreeNode>>) -> Vec<i32> {
// Initialize queue, add root node
let mut que = VecDeque::new();
que.push_back(root.clone());
// Initialize a list to store the traversal sequence
let mut vec = Vec::new();
while let Some(node) = que.pop_front() {
// Queue dequeues
vec.push(node.borrow().val); // Save node value
if let Some(left) = node.borrow().left.as_ref() {
que.push_back(left.clone()); // Left child node enqueues
}
if let Some(right) = node.borrow().right.as_ref() {
que.push_back(right.clone()); // Right child node enqueues
};
}
vec
}
/* Driver Code */
fn main() {
/* Initialize binary tree */
// Use a specific function to convert an array into a binary tree
let root = vec_to_tree(op_vec![1, 2, 3, 4, 5, 6, 7]).unwrap();
println!("Initialize binary tree\n");
print_util::print_tree(&root);
/* Level-order traversal */
let vec = level_order(&root);
print!("\nPrint sequence of nodes in level-order traversal = {:?}", vec);
}