Problem
Write a program to find the n-th ugly number.
Ugly numbers are positive numbers whose prime factors only include 2, 3, 5.
Example:
Input: n = 10
Output: 12
Explanation: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12 is the sequence of the first 10 ugly numbers.
Note:
1 is typically treated as an ugly number.
n does not exceed 1690.
Solution
class Solution:
ugly = sorted(2**a * 3**b * 5**c for a in range(32) for b in range(32) for c in range(32))
def nthUglyNumber(self, n: int) -> int:
return self.ugly[n-1]