hello-algo/codes/rust/chapter_stack_and_queue/deque.rs

/**
 * File: deque.rs
 * Created Time: 2023-02-05
 * Author: sjinzh (sjinzh@gmail.com)
*/

use std::collections::LinkedList;

/* Driver Code */
pub fn main() {
    // 初始化双向队列
    let mut deque: LinkedList<i32> = LinkedList::new();
    deque.push_back(2);     // 添加至队尾
    deque.push_back(5);
    deque.push_back(4);
    deque.push_front(3);    // 添加至队首
    deque.push_front(1);
    print!("双向队列 deque = ");
    inc::print_util::print_queue(&deque);

    // 访问元素
    let peek_first = deque.front().unwrap();    // 队首元素
    print!("\n队首元素 peekFirst = {peek_first}");
    let peek_last = deque.back().unwrap();      // 队尾元素
    print!("\n队尾元素 peekLast = {peek_last}");

    // 元素出队
    let poll_first = deque.pop_front().unwrap();    // 队首元素出队
    print!("\n队首出队元素 pollFirst = {poll_first}，队首出队后 deque = ");
    inc::print_util::print_queue(&deque);
    let poll_last = deque.pop_back().unwrap();      // 队尾元素出队     
    print!("\n队尾出队元素 pollLast = {poll_last}，队尾出队后 deque = ");
    inc::print_util::print_queue(&deque);

    // 获取双向队列的长度
    let size = deque.len();
    print!("\n双向队列长度 size = {size}");

    /* 判断双向队列是否为空 */
    let is_empty = deque.is_empty();
    print!("\n双向队列是否为空 = {is_empty}");
}