problem.md

Problem 39: Combination Sum

Difficulty: Medium

Problem

Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target.

The same repeated number may be chosen from candidates unlimited number of times.

Example

Input: candidates = [2,3,6,7], target = 7,
A solution set is:
[
  [7],
  [2,2,3]
]

Note:

All numbers (including target) will be positive integers.

The solution set must not contain duplicate combinations.