Ugly number.

Author: recherst

Easy/263.Ugly Number.playground/Contents.swift

@@ -0,0 +1,46 @@
+/**
+ An ugly number is a positive integer whose prime factors are limited to 2, 3, and 5.
+
+ Given an integer n, return true if n is an ugly number.
+
+  
+
+ Example 1:
+ Input: n = 6
+ Output: true
+ Explanation: 6 = 2 × 3
+ 
+ Example 2:
+ Input: n = 1
+ Output: true
+ Explanation: 1 has no prime factors, therefore all of its prime factors are limited to 2, 3, and 5.
+ 
+ Example 3:
+ Input: n = 14
+ Output: false
+ Explanation: 14 is not ugly since it includes the prime factor 7.
+  
+
+ Constraints:
+ - -231 <= n <= 231 - 1
+ */
+class Solution {
+    func isUgly(_ n: Int) -> Bool {
+        if n == 0 { return false }
+        var num = n
+        while num % 2 == 0 || num % 3 == 0 || num % 5 == 0 {
+            if num % 2 == 0 {
+                num /= 2
+            }
+            if num % 3 == 0 {
+                num /= 3
+            }
+            if num % 5 == 0 {
+                num /= 5
+            }
+        }
+        
+        if num == 1 { return true }
+        return false
+    }
+}

Easy/263.Ugly Number.playground/contents.xcplayground

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='ios' buildActiveScheme='true' importAppTypes='true'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>

Easy/263.Ugly Number.playground/playground.xcworkspace/contents.xcworkspacedata

@@ -60,6 +60,7 @@
 56. [Valid Anagram](https://github.com/recherst/leetcode-algtorithm/blob/main/Easy/242.Valid%20Anagram.playground/Contents.swift)
 57. [Binary Tree Paths](https://github.com/recherst/leetcode-algtorithm/blob/main/Easy/257.Binary%20Tree%20Paths.playground/Contents.swift)
 58. [Add Digits](https://github.com/recherst/leetcode-algtorithm/blob/main/Easy/258.Add%20Digits.playground/Contents.swift)
+59. [Ugly Number](https://github.com/recherst/leetcode-algtorithm/blob/main/Easy/263.Ugly%20Number.playground/Contents.swift)
 
 #### Medium