Traverse and Print

Walk from the head pointer to null, visiting each node exactly once without random indexing.

Algorithm

The replay labels nodes by value, such as node(20), and never exposes object identity or memory addresses. This Rust DSA implementation uses the same small chain as the rest of the DSA track.

Basic Implementation

basic.rs

struct Node {
    value: i32,
    next: Option<Box<Node>>,
}

fn node(value: i32, next: Option<Box<Node>>) -> Option<Box<Node>> {
    Some(Box::new(Node { value, next }))
}

fn render(head: &Option<Box<Node>>) -> String {
    let mut parts: Vec<String> = Vec::new();
    let mut cursor = head.as_ref();
    while let Some(node) = cursor {
        parts.push(node.value.to_string());
        cursor = node.next.as_ref();
    }
    parts.join(" -> ") + " -> null"
}

fn delete_value(head: Option<Box<Node>>, target: i32) -> Option<Box<Node>> {
    match head {
        Some(mut n) => {
            if n.value == target {
                n.next
            } else {
                n.next = delete_value(n.next, target);
                Some(n)
            }
        }
        None => None,
    }
}

fn main() {
    let head = node(10, node(20, node(30, None)));
    println!("{}", render(&head));
}

Complexity

Time: O(n)
Space: O(1)

Implementation notes

Keep the explicit node and pointer/reference operations; array shortcuts hide the linked-list state this lesson is meant to replay.
The final output prints the chain in a deterministic a -> b -> null form for cross-language comparison.

cursor A cursor reference names the node currently being visited.

null stop Traversal ends when the cursor reaches the null marker.