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.
All numbers (including target) will be positive integers.
The solution set must not contain duplicate combinations.
Input: candidates = [2,3,6,7], target = 7, A solution set is: [ , [2,2,3] ]
Input: candidates = [2,3,5], target = 8, A solution set is: [ [2,2,2,2], [2,3,3], [3,5] ]
- Sort the list at first, so once the remain less than 0, it doesn’t have to add next numbers of the list.
- The process of addition likes deep first sort.