19
08/2015
[LeetCode] Ugly Number
Ugly Number
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.
Credits:
Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.
解题思路:
题意为只有2、3、5三个因子的数成为Ugly Number。1也认为是Ugly Number。因此我们只需要不断的除以2/3/5即可(倘若能够整除)
class Solution {
public:
bool isUgly(int num) {
if(num<=0){
return false;
}
while(num%2==0){
num /= 2;
}
while(num%3==0){
num /= 3;
}
while(num%5==0){
num /= 5;
}
return num==1;
}
};转载请注明:康瑞部落 » [LeetCode] Ugly Number

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