Problem:
Score : 200 points

Problem Statement

Given is an integer N. Find the number of digits that N has in base K.

Notes

For information on base-K representation, see Positional notation - Wikipedia.

Constraints

All values in input are integers.

1 \leq N \leq 10^9

2 \leq K \leq 10

Input

Input is given from Standard Input in the following format:

N K

Output

Print the number of digits that N has in base K.

Sample Input 1

11 2

Sample Output 1

4

In binary, 11 is represented as 1011.

Sample Input 2

1010101 10

Sample Output 2

7

Sample Input 3

314159265 3

Sample Output 3

18

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
public class Main{
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long n = sc.nextInt();
    int k = sc.nextInt();
    long a = 0;
    int count = 0;
    for(int i=0 ; i<n ; i++){
      a = (long)Math.pow(k,i);
      if(n/a>0){
        count++;
      }else{
        count++;
        break;
      }
    }
    if(count==1){
      System.out.println(count);
    }else{
      System.out.println(count-1);
    }

  }
}