Can someone help me with Binary convertor

Question

My 4th test case is not passing. Please someone let me know where my code is lacking

import java.util.Scanner;
public class Program {
public static int toBinary(int n, int k)
{
return (n==0)? 0 :(( n % 2)*k) + toBinary (n/2,k*10);
}
public static void main(String[ ] args) {
Scanner sc = new Scanner(System.in);
int x = sc.nextInt();
int sum = toBinary(x, 1);
System.out.println(sum);
}
}

Answer 1

It's because you store binary representation in a variable of type "int". Your algorithm is doing fine until the "sum" reaches "int" limit (2,147,483,648 or in your case 1,111,111,111). I recommend using this one:

public static String toBinary(int n) {
String bin = "";
while (n > 0) {
bin = (n%2) + bin;
n /= 2;
}
return ;
}