2413. Smallest Even Multiple
Description
Given a positive integer n
, return the smallest positive integer that is a multiple of both 2
and n
.
Example 1:
Input: n = 5 Output: 10 Explanation: The smallest multiple of both 5 and 2 is 10.
Example 2:
Input: n = 6 Output: 6 Explanation: The smallest multiple of both 6 and 2 is 6. Note that a number is a multiple of itself.
Constraints:
1 <= n <= 150
Solutions
Solution 1: Mathematics
If $n$ is even, then the least common multiple (LCM) of $2$ and $n$ is $n$ itself. Otherwise, the LCM of $2$ and $n$ is $n \times 2$.
The time complexity is $O(1)$.
1 2 3 |
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1 2 3 4 5 |
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1 2 3 4 5 6 |
|
1 2 3 4 5 6 |
|
1 2 3 |
|
1 2 3 4 5 6 7 8 |
|
1 2 3 |
|