Build a Singly Linked List

Construct a singly linked list by allocating one node per value and chaining next references. Establishes the node + head + tail model used by every later linked-list lesson.

Algorithm

Canonical input [10, 20, 30, 40] builds the chain head -> 10 -> 20 -> 30 -> 40 -> null with one node appended per step.

Basic Implementation

Basic.java

public class Basic {
    static class Node {
        int value;
        Node next;
        Node(int value) { this.value = value; }
    }

    public static void main(String[] args) {
        int[] values = {10, 20, 30, 40};
        Node head = null;
        Node tail = null;
        for (int v : values) {
            Node node = new Node(v);
            if (head == null) {
                head = node;
            } else {
                tail.next = node;
            }
            tail = node;
        }
    }
}

Complexity

Time: O(n) with a tail pointer
Space: O(n) for the chain

Implementation notes

Java: a small static inner class Node is the idiomatic Node.
The replay never shows object identity; nodes are labelled node(<value>) and the chain view is rendered as 10 -> 20 -> ... -> null.

node chain Each `Node` carries an `int value` and a `Node next` reference (or `null`).