import java.util.Arrays;

class SubsetSum {
    public static boolean canMakeSum(int[] setOfNums, int targetSum, int index) {
	if (setOfNums.length == index) {
	    // base case:
	    // the sum either is or is not the target
	    return targetSum == 0;
	} else {
	    // recursive case:
	    // we must choose to include or exclude the current
	    // number from the running total
	    boolean include = canMakeSum(setOfNums, targetSum - setOfNums[index], index + 1);
	    boolean exclude = canMakeSum(setOfNums, targetSum, index + 1);
	    return include || exclude;
	}
    }
    
    public static void main(String[] args) {
	int[] nums = { 3, 7, 1, 8, -3 };
	int targetSum = 4;
	boolean found = canMakeSum(nums, targetSum, 0);
	System.out.println("For array " + Arrays.toString(nums) + " and target sum = " + targetSum + " found = " + found);

	targetSum = 0;
	found = canMakeSum(nums, targetSum, 0);
	System.out.println("For array " + Arrays.toString(nums) + " and target sum = " + targetSum + " found = " + found);

	targetSum = 20;
	found = canMakeSum(nums, targetSum, 0);
	System.out.println("For array " + Arrays.toString(nums) + " and target sum = " + targetSum + " found = " + found);

	nums = new int[0];
	targetSum = 0;
	found = canMakeSum(nums, targetSum, 0);
	System.out.println("For array " + Arrays.toString(nums) + " and target sum = " + targetSum + " found = " + found);

	targetSum = 1;
	found = canMakeSum(nums, targetSum, 0);
	System.out.println("For array " + Arrays.toString(nums) + " and target sum = " + targetSum + " found = " + found);
    }
}