---
# System prepended metadata

title: \#263 Ugly Number
tags: [leetcode, leetcode-easy]

---

# \#263 Ugly Number
## *給定一數,判斷其是否有不是2或3或5的質因數*
## Log
 - build 20210601 by syhuang

## 初見
 - 用2/3/5去除,除到最後不是1就表示有2/3/5以外的質因數,注意edge case(負數無法質因數分解)
```javascript=
var isUgly = function(n) {
    if(n<=0) return false;
    while(n%2==0) n/=2;
    while(n%3==0) n/=3;
    while(n%5==0) n/=5;
    return (n==1);
};
```
## 備註
## 參考
###### tags: `leetcode`, `leetcode-easy`