Kyselyt

#include <iostream>
#include <cstdlib>
#include <cstdio>

using namespace std;

int pow10(int x) {
    if (x == 0) {
        return 1;
    } else {
        return pow10(x - 1) * 10;
    }
}

int main() {
    char buffer[10];
    cin >> buffer;
    int count = atoi(buffer);

    for (int i = 0; i < count; i++) {
        cin >> buffer;
        int ordinal = atoi(buffer);
        int magnitude = 0;

        while (ordinal > pow10(magnitude) * (magnitude + 1) * 9) {
            magnitude++;
            ordinal -= magnitude * pow10(magnitude - 1) * 9;
        }

        if (magnitude == 0) {
            cout << ordinal << endl;
            continue;
        }

        int value = pow10(magnitude) + (ordinal - 1) / (magnitude + 1);
        char svalue[10];
        sprintf(svalue, "%d", value);

        //cout << "value: " << value << endl; // These lines really came to handy when testing
        //cout << "magnitude: " << magnitude << endl;
        //cout << "ordinal: " << ordinal << endl;
        
        cout << svalue[(ordinal - 1) % (magnitude + 1)] << endl;
    }

    return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: RUNTIME ERROR

*** buffer overflow detected ***: input/code terminated
======= Backtrace: =========
/lib/...