Java+大数+高精度

import java.util.*;
import java.math.*;
import java.text.*;
import java.io.* ;

public class testjava{
    public static void main( String args[] ){
        Scanner cin = new Scanner(new BufferedInputStream(System.in)); 
        BigInteger a,b;
        while( cin.hasNext() ){
            BigInteger t1,t2,t3,t4,t5;
            a = cin.nextBigInteger();
            b = cin.nextBigInteger();
            t1 = a.add( b );
            t2 = a.subtract( b );
            t3 = a.multiply( b );
            t4 = a.divide( b );
            t5 = a.mod( b );
            System.out.println( "和"+t1 );
            System.out.println( t2 );
            System.out.println( t3 );
            System.out.println( t4 );
            System.out.println( t5 );
            //加减乘除+余数
            int s1;
            double s2;
            s1 = t1.intValue();
            s2 = t2.doubleValue();
            System.out.println( s1 );
            System.out.println( s2 );
            //int，double转化位大数
            BigDecimal d1;
            BigDecimal d2 = new BigDecimal("3.141596");
            System.out.println( d2 );
            d2 = d2.setScale( 2,BigDecimal.ROUND_HALF_EVEN);
            //小数位控制
            System.out.println( d2 );
            d1 = new BigDecimal( t1 );
            System.out.println( d1 );//构造方法
            //大整数转化为Decimal
            
            
            int array_int[] = new int[10];
            BigInteger array_Big[] = new BigInteger[10];
            //数组的声明
            array_Big[9]=BigInteger.valueOf(9);//大整数赋值
            System.out.println( array_Big[9] );
            
        }
    }
}