Given an array of integers and a target sum, find all unique subsets that sum up to the target sum, considering each number in the array can be used multiple times.

 Subset Sum Problem with Multiple Solutions

• Description: Given an array of integers and a target sum, find all unique subsets that sum up to the target sum, considering each number in the array can be used multiple times.
• Input: An array of integers arr[] and a target sum target.
• Output: Return a list of lists containing all unique subsets that sum up to the target sum.
• Example:
• Input: arr = [2, 3, 7], target = 7
• Output: [[2, 2, 3], [7]]

Subset Sum Problem with Multiple Solutions

java
import java.util.ArrayList;
import java.util.List;

public class MultipleSubsetSum {
    public static List<List<Integer>> findSubsets(int[] arr, int target) {
        List<List<Integer>> result = new ArrayList<>();
        findSubsetsRecursive(arr, target, new ArrayList<>(), result);
        return result;
    }

    private static void findSubsetsRecursive(int[] arr, int target, List<Integer> current, List<List<Integer>> result) {
        if (target == 0) {
            result.add(new ArrayList<>(current));
            return;
        }
        if (target < 0) return;

        for (int num : arr) {
            current.add(num);
            findSubsetsRecursive(arr, target - num, current, result);
            current.remove(current.size() - 1);
        }
    }

    public static void main(String[] args) {
        int[] arr = {2, 3, 7};
        int target = 7;
        List<List<Integer>> subsets = findSubsets(arr, target);
        for (List<Integer> subset : subsets) {
            System.out.println(subset);
        }
        // Output: [2, 2, 3], [7]
    }
}