Resource page link building in SEO Fundamentals - Time & Space Complexity

Time Complexity: Resource page link building

O(n)

Understanding Time Complexity

When building links from resource pages, it's important to understand how the effort grows as you target more pages.

We want to know how the work increases when the number of resource pages grows.

Scenario Under Consideration

Analyze the time complexity of the following link building steps.

// For each resource page URL in a list
for each resourcePage in resourcePages:
  // Check if the page is relevant
  if isRelevant(resourcePage):
    // Send a personalized outreach email
    sendEmail(resourcePage.contact)
    // Wait for response and follow up if needed
    followUp(resourcePage.contact)

// End of process
    

This code represents reaching out to multiple resource pages to request a link.

Identify Repeating Operations

Look at what repeats as the input grows.

• Primary operation: Looping through each resource page to check relevance and send emails.
• How many times: Once for every resource page in the list.

How Execution Grows With Input

As the number of resource pages increases, the total work grows in a straight line.

Input Size (n)	Approx. Operations
10	About 10 checks and emails
100	About 100 checks and emails
1000	About 1000 checks and emails

Pattern observation: Doubling the pages doubles the work needed.

Final Time Complexity

Time Complexity: O(n)

This means the effort grows directly with the number of resource pages you target.

Common Mistake

[X] Wrong: "Adding more pages won't increase my work much because I can send one email to many at once."

[OK] Correct: Each page usually needs a personalized email, so work grows with pages, not stays flat.

Interview Connect

Understanding how your outreach effort scales helps you plan realistic campaigns and shows you can think about growth clearly.

Self-Check

What if you grouped resource pages by topic and sent one email per group? How would the time complexity change?