Each digit can be represented using a certain number of matches. Your goal is to create the largest possible number using the matches that you have. For example, if you need 6 matches for zero, 7 matches for one, and 8 matches for two, and you have 21 matches, the largest number you can create is 210 (8 + 7 + 6 = 21 matches).
You are given a int matches and an int n. The ith element (zero-indexed) of matches is the number of matches needed to represent the digit i. n is the number of matches you have. Return the largest possible number you can create without extra leading zeros.