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 Lua DSA implementation uses the
same small chain as the rest of the DSA track.
Basic Implementation
basic.lua
local function node(value, next)
return { value = value, next = next }
end
local function render(head)
local parts = {}
local cursor = head
while cursor ~= nil do
parts[#parts + 1] = tostring(cursor.value)
cursor = cursor.next
end
return table.concat(parts, " -> ") .. " -> null"
end
local head = node(10, node(20, node(30, nil)))
print(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 -> nullform 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.