Skill: Add Algorithm Problem

Add a new practice problem to an algorithm pattern section.

When to Use

•Adding a new LeetCode problem to an algorithm pattern
•Creating practice exercises for a topic
•Expanding problem coverage for interview prep

Steps

1. Create the Problem File

Create the file in the problems/ subdirectory of the algorithm topic:

code

docs/learning/algorithms/{topic}/problems/{problem_name}.md

Naming Convention: Use snake_case, descriptive names:

•two_sum_sorted.md
•longest_substring_no_repeat.md
•number_of_islands.md

2. Use the Problem Template

markdown

# Problem Title

**Difficulty**: Easy | Medium | Hard  
**LeetCode**: [#XXX](https://leetcode.com/problems/problem-slug/)

## Problem Statement

Clear description of the problem with constraints.

**Example**:

Input: ... Output: ... Explanation: ...

code


## Approach

Explain the strategy:
1. First insight
2. Key observation
3. Algorithm choice

## Solution

```python
def solution(input):
    """
    Brief description.
    
    Time Complexity: O(?)
    Space Complexity: O(?)
    """
    # Implementation
    pass

# Test
print(solution(test_input))  # Expected output

Step-by-Step Walkthrough

code

Trace through example input showing state at each step.

Personal Notes

Add your own notes, insights, and variations here as you practice this problem.

code


### 3. Link from Parent Index Page

Add a row to the "Practice Problems" table in the parent `index.md`:

```markdown
## Practice Problems

| Problem | Difficulty | Key Concept |
|---------|------------|-------------|
| [New Problem](problems/new_problem.md) | Medium | Key insight |

4. Update Navigation in mkdocs.yml

CRITICAL: Problem pages MUST be added to mkdocs.yml nav or they will cause runtime navigation issues.

Find the algorithm topic in mkdocs.yml and expand it to include the problem:

Before (simple entry):

yaml

          - Sliding Window: learning/algorithms/sliding_window/index.md

After (expanded with problems):

yaml

          - Sliding Window:
              - Overview: learning/algorithms/sliding_window/index.md
              - Problems:
                  - Max Sum Subarray K: learning/algorithms/sliding_window/problems/max_sum_subarray_k.md
                  - New Problem: learning/algorithms/sliding_window/problems/new_problem.md

If the topic already has a Problems: section, just add your new problem to it.

5. Verify

bash

make build  # Should complete without "not included in nav" warnings for your file

Check the output for:

code

INFO - The following pages exist in the docs directory, but are not included in the "nav" configuration:

If your new file appears in this list, you missed step 4.

Checklist

• Created file in {topic}/problems/ directory
• Used correct template with all sections
• Included "Personal Notes" section at end
• Added link in parent index.md table
• Updated mkdocs.yml nav with problem entry
• Verified build succeeds with no nav warnings for your file