Kyselyt

#include <iostream>
#include <cmath>

//Amount of digits in a line where the greatest number is the greatest number which still has n digits
unsigned long amtDigits(unsigned long n){
    if(n == 1) return 9;
    //Largest number
    unsigned long k = (unsigned long)pow(10, n) - 1;

    //Substract the numbers where there are less than n digits, multiply by length of one number,
    //and add the length of the subtracted numbers
    k -=  (unsigned long)pow(10, n - 1) - 1;
    k *= n;
    k += amtDigits(n - 1);

    return k;
}

unsigned long getNum(unsigned long n){
    if(n < 10) return n;

    
    unsigned long i = 2;
    while(true){
        // See if n is in the range of numbers with i digits
        unsigned long bottom = amtDigits(i - 1);
        unsigned long top = amtDigits(i);
        
        if(bottom <= n && n <= top){
            //count n from bottom
           
            n = n - bottom - 1;
            
            //The number n is pointing in
            unsigned long num = (unsigned long)pow(10, i-1) + n / i;
            
            //The requested digit of said number
            unsigned long dig = n - (( n / i ) * i);

            //Index the digit backwards
            dig = i - dig;

            //Get the digit
            return (num % (unsigned long)pow(10, dig)) / (unsigned long)pow(10, dig - 1); 
        }
        i++;
    }
}


 int main(){
    int numCommands;
    std::cin >> numCommands;


    unsigned long commands[numCommands];

    for(int i = 0; i < numCommands; i++){
        std::cin >> commands[i];
    }
    
    for(int i = 0; i < numCommands; i++){
        std::cout << getNum(commands[i]) << "\n";
    }

    return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: ACCEPTED