Note:
 Use recursion
1
is a special number.
 If a number is not divisible to
2, 3, 5
, then it’s not.
Question:
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 2 3 4 5 6 7
 Input: n = 6 Output: true Explanation: 6 = 2 × 3
Input: n = 1 Output: true Explanation: 1 has no prime factors, therefore all of its prime factors are limited to 2, 3, and 5.

Code:
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var isUgly = function (n) { if (n <= 0) return false; if (n === 1) return true; const factors = [2, 3, 5]; return dfs(n);
function dfs(num) { if (factors.includes(num)) return true; return (num % 2 === 0 && dfs(num / 2))  (num % 3 === 0 && dfs(num / 3))  (num % 5 === 0 && dfs(num / 5)); } };
