Kyselyt

#include <iostream>
#include <math.h>

using namespace std;

int main()
{
	unsigned int q = 0;
	cin >> q;
	for (unsigned int i = 0; i < q; i++)
	{
		unsigned long long int k = 0;
		cin >> k;

		unsigned long long int a = 0;
		unsigned long long int gCeiled = 0;

		unsigned long long int result = 0;

		unsigned long long int o = 1;
		bool done = false;
		while (!done)
		{
			gCeiled += o * 9 * pow((unsigned long long int)10, o - 1);
			if (gCeiled > k)
			{
				a = o;
				done = true;
			}
			o++;
		}

		result = pow((unsigned long long int)10, a) - 1 - floor((gCeiled - k) / a);

		unsigned long long int mod = ((gCeiled - k) % a);
		unsigned long long int digit = 0;
		unsigned long long int power = pow((unsigned long long int)10, mod);
		digit = (result / power) % (unsigned long long int)10;

		cout << digit << "\n";
	}
	int a = 0;
	cin >> a;

	return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: WRONG ANSWER