Linked Lists

Recipe	Crates	Categories

Stored data in a linked list

LinkedList represents a doubly linked list, where each element contains a reference to both the next and the previous elements. This allows for efficient insertions and deletions from both ends of the list.

• You can iterate over the elements of the list in both forward and backward directions.
• Adding or removing elements from the front or back of the list is very efficient, with an average time complexity of O(1).
• The list can grow or shrink as needed.

use std::collections::LinkedList;

fn main() {
    // Create a new LinkedList
    let mut list = LinkedList::new();

    // Push elements onto the front of the list
    list.push_front(3);
    list.push_front(2);
    list.push_front(1);

    // Push elements onto the back of the list
    list.push_back(4);
    list.push_back(5);

    // Print the list (elements are printed in the order they were added)
    println!("List elements:");
    for element in &list {
        println!("{}", element);
    }

    // Get the first and last elements (without removing them)
    println!("\nFirst element: {:?}", list.front());
    println!("Last element: {:?}", list.back());

    // Pop elements from the front of the list
    println!("\nPopping from front:");
    while let Some(element) = list.pop_front() {
        println!("Popped: {}", element);
    }

    // Add some more elements
    list.push_front(10);
    list.push_back(20);

    // Pop elements from the back of the list
    println!("\nPopping from back:");
    while let Some(element) = list.pop_back() {
        println!("Popped: {}", element);
    }

    // Add some more elements
    list.push_front(30);
    list.push_back(40);

    // Iterate and modify elements (requires mutable iterator)
    println!("\nIterating and modifying:");
    for element in list.iter_mut() {
        *element *= 2; // Double each element
    }

    for element in &list {
        println!("{}", element);
    }

    // Get the length of the list
    println!("\nNumber of elements in the list: {}", list.len());

    // Check if the list is empty
    println!("Is the list empty? {}", list.is_empty());

    // Clear the list
    list.clear();
    println!("List is empty: {}", list.is_empty());
}