1 import java.util.*; 2 import java.math.*; 3 import java.text.*; 4 import java.io.* ; 5  6 public class testjava{ 7     public static void main( String args[] ){ 8         Scanner cin = new Scanner(new BufferedInputStream(System.in));  9         BigInteger a,b;10         while( cin.hasNext() ){11             BigInteger t1,t2,t3,t4,t5;12             a = cin.nextBigInteger();13             b = cin.nextBigInteger();14             t1 = a.add( b );15             t2 = a.subtract( b );16             t3 = a.multiply( b );17             t4 = a.divide( b );18             t5 = a.mod( b );19             System.out.println( "和"+t1 );20             System.out.println( t2 );21             System.out.println( t3 );22             System.out.println( t4 );23             System.out.println( t5 );24             //加减乘除+余数25             int s1;26             double s2;27             s1 = t1.intValue();28             s2 = t2.doubleValue();29             System.out.println( s1 );30             System.out.println( s2 );31             //int，double转化位大数32             BigDecimal d1;33             BigDecimal d2 = new BigDecimal("3.141596");34             System.out.println( d2 );35             d2 = d2.setScale( 2,BigDecimal.ROUND_HALF_EVEN);36             //小数位控制37             System.out.println( d2 );38             d1 = new BigDecimal( t1 );39             System.out.println( d1 );//构造方法40             //大整数转化为Decimal41             42             43             int array_int[] = new int[10];44             BigInteger array_Big[] = new BigInteger[10];45             //数组的声明46             array_Big[9]=BigInteger.valueOf(9);//大整数赋值47             System.out.println( array_Big[9] );48             49         }50     }51 }