Kyselyt

#include <iostream>
#include <string>

using namespace std;

long pow(int a, int b)
{
	if (b == 0) return 1;
	long t = a;
	for (int i = 1; i < b; i++)
		t *= a;
	return t;
}

long nums(int n)
{
	return ((pow(10, n) - 1) - (pow(10, n - 1) - 1)) * n;
}

char at(long x)
{
	int i = 1;
	long num2 = 0;
	long num = nums(1);
	while (x - num > 0)
	{
		i++;
		num2 = num;
		num += nums(i);
	}
	x -= num2;
	long p = x - 1;
	x = p / i;
	x += pow(10, i - 1);
	string n = to_string(x);
	return n[p % i];
}

int main()
{
	int q;
	cin >> q;
	for (int i = 0; i < q; i++)
	{
		long x;
		cin >> x;
		cout << at(x) << '\n';
	}
	return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: ACCEPTED