【数学】C009_丑数(整除 | 递归)

一、题目描述 Write a program to check whether a given number is an ugly number. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. Input: 6 Output: true Explanation: 6 = 2 × 3 Note: 1 is typically treated as an ugly number. Input is within the 32-bit signed integer range: [−2^31,