LeetCode - Combination Sum

Question Definition

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

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

Note:

• All numbers (including target) will be positive integers.
• The solution set must not contain duplicate combinations. For example, given candidate set [2, 3, 6, 7] and target 7, A solution set is:

  [
  [7],
  [2, 2, 3]
  ]
  

  My Java Solution

  class Solution {
    public List<List<Integer>> combinationSum(int[] candidates, int target) {
        List<List<Integer>> result = new LinkedList<>();
        List<Integer> cur = new LinkedList<>();
        dfs(candidates, target, 0, cur, result);
        return result;
    }
    private void dfs(int[] candidates, int target, int start, List<Integer> cur, List<List<Integer>> result){
        if(target < 0) return;
        if(target == 0){
            result.add(new LinkedList<>(cur));
            return;
        }
  
        for(int i = start; i < candidates.length; i++){
            cur.add(candidates[i]);
            dfs(candidates, target - candidates[i], i, cur, result);
            cur.remove(cur.size() - 1);
        }
    }
  }