Easy
You are given an integer n.
Return the total number of commas used when writing all integers from [1, n] (inclusive) in standard number formatting.
In standard formatting:
Example 1:
Input: n = 1002
Output: 3
Explanation:
The numbers "1,000", "1,001", and "1,002" each contain one comma, giving a total of 3.
Example 2:
Input: n = 998
Output: 0
Explanation:
All numbers from 1 to 998 have fewer than four digits. Therefore, no commas are used.
Constraints:
1 <= n <= 105import kotlin.math.max
class Solution {
fun countCommas(n: Int): Int = max(0, n - 999)
}