八十八、进制转换（一个方法通用）

import java.math.BigInteger;
public class Main {
  public static void main(String[] args) {
  BigInteger b = new BigInteger("67", 10);
  System.out.println(b.toString(2));   //1000011
  }
}

import java.math.BigInteger;
public class Main {
  public static void main(String[] args) {
  BigInteger b = new BigInteger("67", 8);
  System.out.println(b.toString(10));   //55
  }
}

import java.math.BigInteger;
public class Main {
  public static void main(String[] args) {
  BigInteger b = new BigInteger("67", 16);
  System.out.println(b.toString(8));    //147
  }
}