/**
     * Merge two ordered int arrays
     * @param array1 an ordered int[]
     * @param array2 another ordered int[]
     * @return a new ordered array containing all distinct values from array1 and array2
     */
    static int[] merge(int[] array1, int[] array2) {
        int[] result = new int[array1.length + array2.length];
        int ptr1 = 0;
        int ptr2 = 0;
        int resultPtr = 0;
        int val1, val2;
        val1 = array1[ptr1];
        val2 = array2[ptr2];
        do {
            if (val1 < val2) {
                result[resultPtr] = val1;
                resultPtr++;
                ptr1++;
                if (ptr1 < array1.length) {
                    val1 = array1[ptr1];
                }
            } else if (val2 < val1) {
                result[resultPtr] = val2;
                resultPtr++;
                ptr2++;
                if (ptr2 < array2.length) {
                    val2 = array2[ptr2];
                }
            } else {
                result[resultPtr] = val1;
                resultPtr++;
                ptr1++;
                if (ptr1 < array1.length) {
                    val1 = array1[ptr1];
                }
                ptr2++;
                if (ptr2 < array2.length) {
                    val2 = array2[ptr2];
                }
            }
        } while (ptr1 < array1.length && ptr2 < array2.length);
        result = Arrays.copyOfRange(result, 0, resultPtr);
        return result;

    }