Java Math BigInteger.modInverse() 方法

package com.codingdict;



import java.math.*;



public class BigIntegerDemo {



   public static void main(String[] args) {



      // create 3 BigInteger objects

      BigInteger bi1, bi2, bi3;



      // Two numbers are relatively prime if they have no

      // common factors, other than 1.

      bi1 = new BigInteger("7");

      bi2 = new BigInteger("20");



      // perform modInverse operation on bi1 using bi2

      bi3 = bi1.modInverse(bi2);



      String str = bi1 + "^-1 mod " + bi2 + " is " +bi3;



      // print bi3 value

      System.out.println( str );

   }

}