Combination Sum II

Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.

Each number in C may only be used once in the combination.

public class Solution {
    public ArrayList<ArrayList<Integer>> combinationSum2(int[] candidates, int target) {
        ArrayList<ArrayList<Integer>> res = new ArrayList<ArrayList<Integer>>();
        if(candidates.length<=0) return res;
        Arrays.sort(candidates);
        DFS(candidates,target,0,0,res,new ArrayList<Integer>());
        return res;
    }
    public void DFS(int[] can,int target,int sum,int start,ArrayList<ArrayList<Integer>>res,ArrayList<Integer>output){
        if(sum>target) return;
        if(sum==target){
            ArrayList<Integer> temp = new ArrayList<Integer>();
            temp.addAll(output);
            res.add(temp);
            return;
        }
        for(int i=start;i<can.length;i++){
            output.add(can[i]);
            sum+=can[i];
            DFS(can,target,sum,i+1,res,output);
            sum-=output.get(output.size()-1);
            output.remove(output.size()-1);
            while(i<can.length-1 && can[i]==can[i+1]){//delete the duplicates
              i++;
            }
        }
    }
}