Work Schedule

You are given a weekly work schedule encoded as a 7-character string pattern. Each character is either a digit ('0' through '8') representing the hours worked that day, or a question mark ('?') meaning the hours for that day are undecided. An employee must work exactly workHours total hours in the week. For any day marked '?', the maximum hours you can assign is dayHours. Your job is to produce all possible valid schedules by substituting every '?' in pattern with a digit…