Check if a Number is an Ugly Number in Python

Suppose we have a number n, we have to check whether its prime factors only include 2, 3 or 5 or not.

So, if the input is like n = 18, then the output will be True, as 18's prime factors are 2 and 3.

To solve this, we will follow these steps −

• if n < 0, then
  • return False
• factor := a list with elements [2,3,5]
• for each i in factor, do
  • while n mod i is same as 0, do
    • n := n / i
• return true when n is same as 1, otherwise false

Let us see the following implementation to get better understanding −

Example

 Live Demo

class Solution:
   def solve(self, n):
      if n < 0:
         return False
      factor = [2,3,5]
      for i in factor:
         while n%i ==0:
            n/=i
      return n==1
ob = Solution()
print(ob.solve(18))

Input

18

Output

True