高精度练习

package Deom1;
import java.math.BigInteger;
import java.util.Scanner;
import java.util.SortedMap;
//加法练习
public class lx {
    public static void main(String [] args) {
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        String str = sc.next();
        BigInteger b = new BigInteger(s);　　//BigInteger继承自Number类，可表示任意长度的整数。BigInteger用等号可以直接进行复制，而不是引用地址
        BigInteger big = new BigInteger(str);
        System.out.println(b.add(big));
    }
}

package Deom1;
import java.math.BigInteger;
import java.util.Scanner;
import java.util.SortedMap;
//乘法练习
public class lx {
    public static void main(String [] args) {
        Scanner sc = new Scanner(System.in);
        BigInteger a = sc.nextBigInteger();
        BigInteger b = sc.nextBigInteger();
        BigInteger c = a.multiply(b);
        System.out.println(c);
    }
}