Kyselyt

import java.util.Scanner;

public class kyselyt1 {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int amountOfCases = Integer.parseInt(in.nextLine());
		for (int i = 0; i < amountOfCases; i++) {
			System.out.println(performFunction(Long.parseLong(in.nextLine())));
		}
		in.close();
	}

	public static long performFunction (long num) {
		long nd = (9 * (String.valueOf(num).length() + 1) * ((long) Math.pow(10, String.valueOf(num).length())) - ((long) Math.pow(10, String.valueOf(num).length() + 1)) + 1) /9; 
		
		long pos = String.valueOf(num).length() - ((nd - num) % String.valueOf(num).length());
		
		long ans = Character.getNumericValue(String.valueOf(((long) Math.pow(10, String.valueOf(num).length())) - 1 - (long) Math.floor((nd - num) / String.valueOf(num).length())).charAt((int) pos - 1));

		return ans;
	}
}

Test 1

Group: 1

Verdict: RUNTIME ERROR

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of...

Test 2

Group: 2

Verdict: RUNTIME ERROR

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of...

Test 3

Group: 3

Verdict: RUNTIME ERROR

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of...