package leetcode_1To300;

/**
 * 本代码来自 Cspiration，由 @Cspiration 提供
 * 题目来源：http://leetcode.com
 * - Cspiration 致力于在 CS 领域内帮助中国人找到工作，让更多海外国人受益
 * - 现有课程：Leetcode Java 版本视频讲解（1-900题）（上）（中）（下）三部
 * - 算法基础知识（上）（下）两部；题型技巧讲解（上）（下）两部
 * - 节省刷题时间，效率提高2-3倍，初学者轻松一天10题，入门者轻松一天20题
 * - 讲师：Edward Shi
 * - 官方网站：https://cspiration.com
 * - 版权所有，转发请注明出处
 */
public class _263_UglyNumber {
    /**
     * 263. Ugly Number
     * Ugly numbers are positive numbers whose prime factors only include 2, 3, 5.
     * For example, 6, 8 are ugly while 14 is not ugly since it includes another prime factor 7.

     Note that 1 is typically treated as an ugly number.

     time : O(n)
     space : O(1)

     * @param num
     * @return
     */

    public boolean isUgly(int num) {
        if (num == 1) return true;
        if (num == 0) return false;
        while (num % 2 == 0) num /= 2;
        while (num % 3 == 0) num /= 3;
        while (num % 5 == 0) num /= 5;
        return num == 1;
    }

    public boolean isUgly2(int num) {
        for (int i = 2; i < 6 && num > 0; i++) {
            while (num % i == 0) {
                num /= i;
            }
        }
        return num == 1;
    }
}