大数加法和乘法（高精度）

使用java BigInteger

大数加法 http://www.51nod.com/onlineJudge/questionCode.html#!problemId=1005

import java.math.BigInteger;
import java.util.Scanner;

public class Nim {

    public static void main(String[] args) {
        Scanner cin=new Scanner(System.in);
        BigInteger a=cin.nextBigInteger(),b=cin.nextBigInteger();
        System.out.println(a.add(b));
    }
    
}

大数乘法 http://www.51nod.com/onlineJudge/questionCode.html#!problemId=1027

import java.math.BigInteger;
import java.util.Scanner;

public class Nim {

	public static void main(String[] args) {
		Scanner cin=new Scanner(System.in);
		BigInteger a=cin.nextBigInteger(),b=cin.nextBigInteger();
		System.out.println(a.multiply(b));
	}
	
}