Find the smallest positive integer value that cannot be represented as sum of any subset of a given array

smallest.java

class FindSmallestInteger {

    public static void main(String[] args) {
        int arr3[] = {1, 1, 1, 3};
        System.out.println(findMinImpossible(arr3));
    }

    public static int findMinImpossible(int[] a) {
        int maxPossible = 0;

        if (a.length == 0 || a[0] != 1) {
            return maxPossible + 1;
        }

        // we have verified that 1 exists in the array.
        maxPossible = 1;

        for (int i = 1; i < a.length; i++) {
            // if the current element is greater than (maxPossible + 1)
            // that leaves a gap at: maxPossible + 1
            if (a[i] > maxPossible + 1) {
                break;
            }

            maxPossible += a[i];
        }


        return maxPossible + 1;
    }
}