Find first n numbers with given set of digits Java

PROGRAM TO FIND NTH NUMBER WITH DIGITS IN {0, 1, 2, 3, 4, 5}




import java.util.*;

 

class MAIN{

 

static int ans(int n)

{

     

    // If the Number is less than 6 return

    // the number as it is.

    if (n < 6)

    {

        return n;

    }

     

    // Call the function again and again

    // the get the desired result.

    // And convert the number to base 6.

    return n % 6 + 10 * (ans(n / 6));

}

 

static int getSpecialNumber(int N)

{

     

    // Decrease the Number by 1 and Call

    // ans function to convert N to base 6

    return ans(--N);

}

 

/*

 * Example:- Input: N = 17 Output: 24

 *

 * Explaination:- decrease 17 by 1 N = 16 call ans() on 16

 *

 * ans(): 16%6 + 10*(ans(16/6)) since 16/6 = 2 it is less

 * than 6 the ans returns value as it is. 4 + 10*(2) = 24

 *

 * hence answer is 24.

 */

// Driver code

public static void main(String[] args)

{

    int N = 17;

    int answer = getSpecialNumber(N);

     

    System.out.println(answer);

}

}







OUTPUT:

24

CREDITS: https://www.geeksforgeeks.org/n-th-number-with-digits-in-0-1-2-3-4-5/