Combination Sum II

public class Solution {
    public ArrayList<ArrayList<Integer>> ret;
    public ArrayList<Integer> cur;
    public ArrayList<ArrayList<Integer>> combinationSum2(int[] candidates, int target) {
        // Start typing your Java solution below
        // DO NOT write main() function
        cur = new ArrayList<Integer>();
        ret = new ArrayList<ArrayList<Integer>>();
        Arrays.sort(candidates);
        dfs(candidates,0,target,cur);
        return ret;
        
    }
    private void dfs(int[] num,int index,int target,ArrayList<Integer> cur){
        if(index==num.length)return;
        if(target<num[index])return;
        else{
            if(target==num[index]){
                cur.add(num[index]);
                if(!ret.contains(cur))
                    ret.add(new ArrayList<Integer>(cur));
                cur.remove(cur.size()-1);
                dfs(num,index+1,target,cur);
            }
            else{
                cur.add(num[index]);
                dfs(num,index+1,target-num[index],cur);
                cur.remove(cur.size()-1);
                dfs(num,index+1,target,cur);
            }
        }
    }
}