Generate nth ugly number
Problem Given an integer n, return the nth ugly number. Ugly Number Definition Examples Example 1: Input: n = 10 Output: 12 Explanation: [1, 2, 3, 4, 5, 6, 8, 9, 10, 12] is the sequence of the first 10 ugly numbers. Example 2: Input: n = 1 Output: 1 Explanation: 1 has no prime factors, therefore all of its prime factors are limited to 2, 3, and 5. ...