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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. For example, 6, 8 are ugly while 14 is not ugly since it includes another prime factor 7.Note that 1 is typically treated as an ugly number. |
题意：判断一个数是不是丑数。只能被2,3,5因子的。
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public class Solution {
public boolean 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?true:false;
}
} |
PS:直接做除法就行。
本文转自 努力的C 51CTO博客，原文链接:http://blog.51cto.com/fulin0532/1905431