import java.util.*;

/**
 * Integer Base Conversion
 * base-conversion
 * 
 * 
 * Input:
 *     num: A base-10 integer to convert.
 *     b: The target base to convert it to.
 * 
 * Precondition:
 *     num > 0, 2 <= b <= 36.
 * 
 * Output:
 *     A string representing the value of num in base b.
 * 
 * Example:
 *     >>> to_base(31, 16)
 *     '1F'
 *
 * @author derricklin
 */
public class TO_BASE {
    public static String to_base(int num, int b) {
        String result = "";
        String alphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        int i;
        while (num > 0) {
            i = num % b;
            num = num / b; // floor division?
            result = String.valueOf(alphabet.charAt(i))+result;
        }

        return result;
    }
}