As part of a larger scale project, you need to write a component which generates consecutive positive integers. Only certain digits may appear in the input and in the integers generated, and leading zeros aren't allowed.
You are given a int[] **allowed** containing the list of allowed digits, and a String **current** representing the current integer. Return a String representing the first integer larger than **current** composed only of digits in **allowed**.
If **current** represents an invalid integer according to the first paragraph, return "`INVALID INPUT`" (quotes for clarity). |