[FEATURE REQUEST] Add Combination Sum algorithm using recursion (java) (hacktoberfest'25) #6804
Description
What would you like to Propose?
I would like to propose adding the Combination Sum algorithm implementation under
Java/src/main/java/com/thealgorithms/recursion/.
This algorithm solves a classic recursion and backtracking problem finding all unique combinations of numbers that sum up to a target value. It's a popular interview and DSA question that fits perfectly in the recursion package.
Issue details
Given an array of distinct integers candidates and a target integer target, the task is to find all unique combinations of candidates where the chosen numbers sum to the target.
Each number in candidates may be used an unlimited number of times.
Example:
Input: candidates = [2,3,6,7], target = 7
Output: [[2,2,3],[7]]
Proposed Implementation Details
- Implemented using recursion
Benefits:
- Adds an essential recursive algorithm often used in coding interviews and competitive programming.
Additional Information
Reference: LeetCode Problem 39 - Combination Sum