Submission

Score: 70

User: Ratthathammanoon

Problemset: เลขหลักของผลคูณ

Language: cpp

Time: 0.002 second

Submitted On: 2025-10-12 21:43:49

#include <stdio.h>

int main() {
    int X;
    long long int A, B, C, u = 1;

    scanf("%lld", &A);
    scanf("%lld", &B);
    scanf("%d", &X);

    C = A * B;

    long long temp = C;
    if (temp < 0) temp = -temp;
    if (temp == 0) {
        printf("0");
        return 0;
    }

    int digits = 0;
    while (temp > 0) {
        temp /= 10;
        digits++;
    }

    if (X > digits) {
        printf("-");
        return 0;
    }

    for (int i = 0; i < digits - X; i++) {
        u *= 10;
    }

    if (C < 0) C = -C;
    C /= u;
    C %= 10;

    printf("%lld", C);

    return 0;
}