Kyselyt

#include <iostream>
#include <string>
#include <vector>
#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 int num = k;
		unsigned long long int n = 0;
		while (num > 0)
		{
			num = num / 10;
			n++;
		}
		unsigned long long int nums = 0;
		if (n > 1)
		{
			for (unsigned long long int o = 1; o < n; o++)
			{
				if (nums + o * 9 * pow(10, o - 1) < k)
				{
					nums += o * 9 * pow(10, o - 1);
				}
				else
				{
					break;
				}
			}
		}

		unsigned long long int output = (k - nums) / n;

		vector<unsigned int> digits;
		unsigned long long int lK = output;
		while (lK > 0)
		{
			digits.push_back(lK % 10);
			lK /= 10;
		}
		unsigned int mod = ((k - nums) % n) + 1;

		if (mod > 0 && mod <= digits.size())
		{
			output = digits[digits.size() - mod];
		}
		else
		{
			output = digits[digits.size() - 1];
		}

		cout << output << "\n";
	}

	int a;
	cin >> a;

	return 0;
}

Test 1

Group: 1

Verdict: RUNTIME ERROR

Test 2

Group: 2

Verdict: WRONG ANSWER

Test 3

Group: 3

Verdict: WRONG ANSWER