LeetCode-in-Java
263. Ugly Number
Easy
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 = 8
Output: true
Explanation: 8 = 2 × 2 × 2
Example 3:
Input: n = 14
Output: false
Explanation: 14 is not ugly since it includes the prime factor 7.
Example 4:
Input: n = 1
Output: true
Explanation: 1 has no prime factors, therefore all of its prime factors are limited to 2, 3, and 5.
Constraints:
-231 <= n <= 231 - 1
Solution
public class Solution {
public boolean isUgly(int n) {
if (n == 1) {
return true;
} else if (n <= 0) {
return false;
}
int[] factors = new int[] {2, 3, 5};
for (int factor : factors) {
while (n > 1 && n % factor == 0) {
n /= factor;
}
}
return n == 1;
}
}