Q14.java

import java.util.ArrayList;

public class Q14 {
    public static void main(String[] args) {
        int []a = new int[]{ 2 ,3 ,4 ,5};
        ArrayList<Integer> b = new ArrayList<> ();
        System.out.println (repearsub(a , b , 0 , 7 ,new ArrayList<> ()));
    }

    private static ArrayList<ArrayList<Integer>> repearsub(int[] a, ArrayList<Integer> b, int idx, int target , ArrayList<ArrayList<Integer>> k ) {
        if(idx == a.length ){
            if(target == 0){
                k.add (new ArrayList<> (b));
                return k;
            }
            return k ;
        }
        if(target >= a[idx]){
            b.add (a[idx]);
            repearsub(a , b , idx , target - a[idx], k);
            b.remove (b.size () - 1 );
        }

        repearsub (a , b , idx + 1 , target , k );


        return k;
    }
}