1class Solution {2    public List<List<Integer>> combinationSum(int[] candidates, int target) {3        Arrays.sort(candidates);4        List<List<Integer>> result = new ArrayList<>();5        search(candidates, 0, target, new ArrayList<>(), result);6        return result;7    }8    private void search(int[] nums, int start, int remaining, List<Integer> path, List<List<Integer>> result) {9        if (remaining == 0) {10            result.add(new ArrayList<>(path));11            return;12        }13        for (int i = start; i < nums.length; i++) {14            if (nums[i] > remaining) break;15            path.add(nums[i]);16            search(nums, i, remaining - nums[i], path, result);17            path.remove(path.size() - 1);18        }19    }20}