dsa/data_structures/
linked_list.rs

1use crate::data_structures::node::Node;
2
3/// A singly-linked list.
4///
5/// This structure represents a `LinkedList` where each node stores
6/// a value of type `T` and links to the next node in the sequence.
7pub struct LinkedList<T> {
8    /// The head node of the `LinkedList`,
9    /// or `None` if the list is empty.
10    head: Option<Box<Node<T>>>
11}
12
13impl<T> LinkedList<T> {
14    /// Creates a new and empty `LinkedList`.
15    ///
16    /// # Examples
17    ///
18    /// ```
19    /// use dsa::data_structures::linked_list::LinkedList;
20    /// 
21    /// let list: LinkedList<i32> = LinkedList::new();
22    /// assert!(list.is_empty());
23    /// ```
24    pub fn new() -> Self {
25        LinkedList { head: None }
26    }
27
28    /// Adds a value to the front of the `LinkedList`.
29    ///
30    /// This method creates a new node containing the given value
31    /// and makes it the new head of the list.
32    ///
33    /// # Examples
34    ///
35    /// ```
36    /// use dsa::data_structures::linked_list::LinkedList;
37    /// 
38    /// let mut list = LinkedList::new();
39    /// list.push_front(10);
40    /// list.push_front(20);
41    /// assert!(!list.is_empty());
42    /// ```
43    pub fn push_front(&mut self, value: T) {
44        let mut new_node = Box::new(
45            Node::new(
46                value,
47                None
48            )
49        );
50
51        new_node.next = self.head.take();
52        self.head = Some(new_node);
53    }
54
55    /// Removes and returns the value from the front of the `LinkedList`.
56    ///
57    /// If the list is empty, this method returns `None`. Otherwise,
58    /// it removes the head node and returns its value.
59    ///
60    /// 
61    /// # Returns
62    /// An `Option<T>` optional generic type based on whether the topmost node was popped
63    /// from the list
64    /// - `Some` node is returned if this `LinkedList` has a head, otherwise `None`
65    /// 
66    /// # Examples
67    ///
68    /// ```
69    /// use dsa::data_structures::linked_list::LinkedList;
70    /// 
71    /// let mut list = LinkedList::new();
72    ///
73    /// list.push_front(10);
74    /// list.push_front(20);
75    /// assert_eq!(list.pop_front(), Some(20));
76    /// assert_eq!(list.pop_front(), Some(10));
77    /// assert!(list.is_empty());
78    /// ```
79    pub fn pop_front(&mut self) -> Option<T> {
80        if let Some(node) = self.head.take() {
81            self.head = node.next;
82            Some(node.value)
83        } else {
84            None
85        }
86    }
87
88    /// Checks whether the `LinkedList` is empty.
89    ///
90    /// # Returns
91    /// A `bool`, `true` or `false`, based on whether this `LinkedList` is
92    /// empty
93    ///
94    /// # Examples
95    ///
96    /// ```
97    /// use dsa::data_structures::linked_list::LinkedList;
98    /// 
99    /// let mut list = LinkedList::new();
100    /// assert!(list.is_empty());
101    /// list.push_front(10);
102    /// assert!(!list.is_empty());
103    /// ```
104    pub fn is_empty(&self) -> bool {
105        self.head.is_none()
106    }
107}
dsa/data_structures/linked_list.rs

dsa/data_structures/
linked_list.rs
