3871. Count Commas in Range II

class Solution {
    public long countCommas(long n) {
        long result = 0;
        
        long threshold = 1000L; // 4-digit numbers → 1 comma
        
        while (threshold <= n) {
            result += (n - threshold + 1);
            threshold *= 1000L; // next comma level
        }
        
        return result;
    }
}

class Solution:
    def countCommas(self, n):
        result = 0
        threshold = 1000

        while threshold <= n:
            result += (n - threshold + 1)
            threshold *= 1000

        return result

class Solution {
public:
    long long countCommas(long long n) {
        long long result = 0;
        long long threshold = 1000;

        while (threshold <= n) {
            result += (n - threshold + 1);
            threshold *= 1000;
        }

        return result;
    }
};

class Solution {
    countCommas(n) {
        let result = 0;
        let threshold = 1000;

        while (threshold <= n) {
            result += (n - threshold + 1);
            threshold *= 1000;
        }

        return result;
    }
}