2520. Count the Digits That Divide a Number
Description
Given an integer num
, return the number of digits in num
that divide num
.
An integer val
divides nums
if nums % val == 0
.
Example 1:
Input: num = 7 Output: 1 Explanation: 7 divides itself, hence the answer is 1.
Example 2:
Input: num = 121 Output: 2 Explanation: 121 is divisible by 1, but not 2. Since 1 occurs twice as a digit, we return 2.
Example 3:
Input: num = 1248 Output: 4 Explanation: 1248 is divisible by all of its digits, hence the answer is 4.
Constraints:
1 <= num <= 109
num
does not contain0
as one of its digits.
Solutions
Solution 1: Enumeration
We directly enumerate each digit $val$ of the integer $num$, and if $val$ can divide $num$, we add one to the answer.
After the enumeration, we return the answer.
The time complexity is $O(\log num)$, and the space complexity is $O(1)$.
1 2 3 4 5 6 7 |
|
1 2 3 4 5 6 7 8 9 10 11 |
|
1 2 3 4 5 6 7 8 9 10 11 12 |
|
1 2 3 4 5 6 7 8 |
|
1 2 3 4 5 6 7 8 9 |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 |
|
1 2 3 4 5 6 7 8 9 10 11 |
|
Solution 2
1 2 3 4 5 6 7 8 9 |
|
1 2 3 4 5 6 7 8 9 |
|