combination sum (variation), Java

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//'main' method must be in a class 'Rextester'.
//Compiler version 1.8.0_111

import java.util.*;
import java.lang.*;

class Rextester
{  
    //[2,3,5,6,7]
    public static List<Integer> subsetSum(int[] candidates,int target){
        List<Integer> out = new ArrayList<>();
        helper(candidates,target,out,0);
        return out;
    }
    public static boolean helper(int[] candidates,int target,List<Integer> lst,int index){
        if(target==0)
            return true;
        if(target<0)
            return false;
        for(int i=index;i<candidates.length;i++){
            lst.add(i);
            if(!helper(candidates,target-candidates[i],lst,i+1))
                lst.remove(lst.size()-1);
            else
                return true;
        }
        return false;
    }
    public static void main(String args[])
    {
        System.out.println("Hello, World!");
        List<Integer> lst = subsetSum(new int[]{2,3,5,6},7);
        for(Integer i:lst){
                System.out.print(i+" ");
        }
    }
}

[ + ] Show input
Compilation time: 0.93 sec, absolute running time: 0.18 sec, cpu time: 0.15 sec, memory peak: 18 Mb, absolute service time: 1,13 sec