Linked Structures

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 Go DSA implementation uses the same small chain as the rest of the DSA track.

cursor A cursor reference names the node currently being visited.
null stop Traversal ends when the cursor reaches the null marker.

Basic Implementation

basic.go
Replay: real traced execution (multi-file project)
package main

import (
	"fmt"
	"strings"
)

type Node struct {
	Value int
	Next  *Node
}

func render(head *Node) string {
	parts := []string{}
	for cursor := head; cursor != nil; cursor = cursor.Next {
		parts = append(parts, fmt.Sprint(cursor.Value))
	}
	return strings.Join(parts, " -> ") + " -> null"
}

func main() {
	head := &Node{10, &Node{20, &Node{30, nil}}}
	fmt.Println(render(head))
}

  1. head ← 10 -> 20 -> 30 -> null

    1package main
    values this step10 -> 20 -> 30 -> nullhead

  2. output ← 10

    14parts := []string{}15for cursor := head; cursor != nil; cursor = cursor.Next {16	parts = append(parts, fmt.Sprint(cursor.Value))
    values this step10outputnode(10)cursor

  3. output ← 10 -> 20

    14parts := []string{}15for cursor := head; cursor != nil; cursor = cursor.Next {16	parts = append(parts, fmt.Sprint(cursor.Value))
    values this step10 -> 20outputnode(20)cursor

  4. output ← 10 -> 20 -> 30 -> null

    14parts := []string{}15for cursor := head; cursor != nil; cursor = cursor.Next {16	parts = append(parts, fmt.Sprint(cursor.Value))
    values this step10 -> 20 -> 30 -> nulloutputnode(30)cursor

  5. stdout ← 10 -> 20 -> 30 -> null

    15for cursor := head; cursor != nil; cursor = cursor.Next {16	parts = append(parts, fmt.Sprint(cursor.Value))17}
    values this step10 -> 20 -> 30 -> nullstdout10 -> 20 -> 30 -> nulloutput

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.