Kyselyt

#include <iostream>

using namespace std;
typedef long long ll;
typedef __int128 lll;

ll q;

lll pow(lll k, lll e) {
	if (e == 0) return 1;
	lll res = 1;
	for (int i = 0; i < e; ++i) res *= k;
	return res;
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cin >> q;
	for (int cq = 0; cq < q; ++cq) {
		ll k;
		cin >> k;
		lll n = 1;
		lll nsti = 1;
		while (true) {
			lll nxsti;
			if (n > 1) nxsti = nsti + (pow(10, n)-pow(10, n-1))*n;
			else nxsti = nsti + 9;
			if (nxsti <= k) {
				nsti = nxsti;
				n++;
			}
			else break;
		}
		lll loc = k-nsti;
		lll num = pow(10, n-1)+(loc/n);
		num /= pow(10, (n-1)-loc%n);
		cout << (int)(num%10) << "\n";
	}	
	return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: ACCEPTED