LC-39-combination-sum.md

44 - Combination Sum

Jira Ticket: LND-17
LeetCode: https://leetcode.com/problems/combination-sum
Pattern: Subsets
Difficulty: Medium
Status: To Do
Priority: Medium

Labels: Backtracking, Medium
Created: 2025-08-21
Last Updated: 2025-08-22

---

📝 Problem Statement

Problem URL: https://leetcode.com/problems/combination-sum Problem Description: Solve the Combination Sum coding problem according to the LeetCode description. Visit the problem URL for the complete description and examples. Difficulty: Medium Category: Backtracking

---

🤔 Initial Thoughts

Understanding the Problem

• What are we asked to find/compute?
• What are the inputs and outputs?
• What are the edge cases?

Pattern Recognition

Why Subsets?

What clues in the problem point to this pattern?

---

💡 Approach

Brute Force (if applicable)

Idea:

Time Complexity: O(?)
Space Complexity: O(?)

Optimized Approach

Idea:

Algorithm Steps: 1. 2. 3.

Time Complexity: O(?)
Space Complexity: O(?)

---

🎨 Visual Explanation

Example: 

Step 1: 
Step 2: 
Step 3: 

---

💻 Implementation

# Your solution here
def solution():
    pass

Code Explanation

---

🧪 Test Cases

Test Case 1: Basic Example

Input: 
Expected Output: 
Actual Output: 
Status: ⏳ Not Tested

Test Case 2: Edge Case - Empty Input

Input: 
Expected Output: 
Actual Output: 
Status: ⏳ Not Tested

Test Case 3: Edge Case - Single Element

Input: 
Expected Output: 
Actual Output: 
Status: ⏳ Not Tested

---

📊 Complexity Analysis

Time Complexity: O(?)

Breakdown:

Space Complexity: O(?)

Breakdown:

---

🎓 Key Learnings

What I Learned

Mistakes I Made

Pattern Insights

• When to use subsets:
• When NOT to use this pattern:

---

🔗 Similar Problems

---

📚 Resources

• Pattern Guide
• LeetCode Discussion: https://leetcode.com/problems/combination-sum/discuss/

---

✅ Progress Checklist

• Problem understood
• Pattern identified
• Brute force solution
• Optimized solution
• All test cases pass
• Complexity analyzed
• Code reviewed
• Learnings documented
• Jira ticket updated

---

Status: 🔴 Not Started
Last Updated: 2025-08-22