import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

public class combinationSumII {

public List<List<Integer>> combinationSum(int[] candidates, int target) {

List<List<Integer>> res = new ArrayList<>();

if (candidates == null || candidates.length == 0) return res;

Arrays.sort(candidates);

helper(res, new ArrayList<>(), candidates, target, 0);

return res;

}

public void helper(List<List<Integer>> res, List<Integer> list, int[] candidates, int target, int start) {

if (target == 0) {

res.add(new ArrayList<>(list));

return;

}

if(target<0)return;

for (int i = start; i< candidates.length; i++) {

if(i!=start && candidates[i]==candidates[i-1]) continue;

list.add(candidates[i]);

helper(res, list, candidates, target - candidates[i], i+1);

list.remove(list.size() - 1);

}

}

public static void main(String[] args) {

// TODO Auto-generated method stub

int nums[]= {2,5,2,1,2};

combinationSumII one=new combinationSumII();

one.combinationSum(nums,5);

}

}