combination sum ii(no duplicate numbers)

class  {
    public List<List<Integer>> combinationSum2(int[] candidates, int target) {     
     List<List<Integer>> list = new ArrayList<>();
    Arrays.sort(candidates);
    backtrack(list, new ArrayList<>(), candidates, target, 0);
    return list;
}

private void backtrack(List<List<Integer>> list, List<Integer> tempList, int [] nums, int remain, int start){
    if(remain < 0) return;
    else if(remain == 0) list.add(new ArrayList<>(tempList));
    else{ 
        for(int i = start; i < nums.length; i++){
            if(i>start&&(nums[i]==nums[i-1])) continue;
            tempList.add(nums[i]);
            backtrack(list, tempList, nums, remain - nums[i], i+1); 
            tempList.remove(tempList.size() - 1);
        }
    }
}
}