高精度

java的高精度比较简单，因为有BigInteger和BigDecimal这两个类，实在是太好用了捏。

• 高精度加法：

  BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
  BigInteger a = new BigInteger(bf.readLine());
  BigInteger b = new BigInteger(bf.readLine());
  System.out.println(a.add(b));

• 高精度减法：

  BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
  BigInteger a = new BigInteger(bf.readLine());
  BigInteger b = new BigInteger(bf.readLine());
  System.out.println(a.subtract(b));

• 高精度乘法：

  BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
  BigInteger a = new BigInteger(bf.readLine());
  BigInteger b = new BigInteger(bf.readLine());
  System.out.println(a.multiply(b));

• 高精度除法：

  BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
  BigInteger a = new BigInteger(bf.readLine());
  BigInteger b = new BigInteger(bf.readLine());
  System.out.println(a.divide(b));//输出商
  System.out.println(a.mod(b));//输出余数