Submission

PPPPPPPPPP

Score: 100

User: KuyHeeTad

Problemset: J.Nine Khanaphat

Language: c

Time: 0.001 second

Submitted On: 2024-10-14 03:55:32

#include <stdio.h>

long long count_nines(long long n) {
    long long count = 0, factor = 1;
    while (n / factor > 0) {
        long long lower = n - (n / factor) * factor;
        long long current_digit = (n / factor) % 10;
        long long higher = n / (factor * 10);
        
        if (current_digit < 9) {
            count += higher * factor;
        } else if (current_digit == 9) {
            count += higher * factor + lower + 1;
        } else {
            count += (higher + 1) * factor;
        }
        factor *= 10;
    }
    return count;
}

int main() {
    long long A, B;
    scanf("%lld %lld", &A, &B);

    
    long long result = count_nines(B) - count_nines(A - 1);
    printf("%lld\n", result);

    return 0;
}