Write a program to check whether a given number is an ugly number.
Ugly numbers are positive numbers whose prime factors only include 2, 3, 5.
Example 1:
Input: 6 Output: true Explanation: 6 = 2 × 3 Example 2:
Input: 8 Output: true Explanation: 8 = 2 × 2 × 2 Example 3:
Input: 14 Output: false Explanation: 14 is not ugly since it includes another prime factor 7. Note:
1 is typically treated as an ugly number. Input is within the 32-bit signed integer range: [−231, 231 − 1].
public class Solution {
public bool IsUgly(int num) {
if(num <= 0){
return false;
}
while(num%2==0){
num=num/2;
}
while(num%3==0){
num=num/3;
}
while(num%5==0){
num=num/5;
}
return num==1;
}
}Time Complexity: O(n)
Space Complexity: O(1)
