题目描述
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:
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Input: 6
Output: true
Explanation: 6 = 2 × 3
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Example 2:
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Input: 8
Output: true
Explanation: 8 = 2 × 2 × 2
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Example 3:
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Input: 14
Output: false
Explanation: 14 is not ugly since it includes another prime factor 7.
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代码实现
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class {
public:
bool isUgly(int num) {
if (num < 1)
return false;
while (num % 2 == 0) {
num /= 2;
}
while (num % 3 == 0) {
num /= 3;
}
while (num % 5 == 0) {
num /= 5;
}
return num == 1;
}
};
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