关于大数的四则运算

　　本文是在我的另一个博客中copy过来的，感觉博客园比较适合写代码就迁过来了

　　好久都没有写过日志了，前两天去面试，看到面试题中有关于大数操作的问题，所以回来以后就总结了一下，供笔试着还有要参加acm的同学做一些参考。

先说一下大数相加：

 1 package com.my.lucene;
 2 
 3  
 4 import java.math.BigInteger;
 5 
 6  
 7 public class test {
 8 public static void main(String[] args) {
 9 String a = "15432321321223123231321"; String  b = "2121212121214354343544354354";
10 BigInteger bg = new BigInteger(a);
11 BigInteger gBigInteger= bg.add(new BigInteger(b));
12 System.out.println(gBigInteger);
13 }
14 }
15 大数相减： 
16 package com.my.lucene;
17 
18 
19 import java.math.BigInteger;
20 
21 
22 public class test {
23 public static void main(String[] args) {
24 String a = "15432321321223123231321"; String  b = "2121212121214354343544354354";
25 BigInteger bg = new BigInteger(a);
26 BigInteger gBigInteger= bg.subtract(new BigInteger(b));
27 System.out.println(gBigInteger);
28 }
29 }

View Code

大数相乘：

 1 package com.my.lucene;
 2 
 3 
 4 import java.math.BigInteger;
 5 
 6 
 7 public class test {
 8 public static void main(String[] args) {
 9 String a = "15432321321223123231321"; String  b = "2121212121214354343544354354";
10 BigInteger bg = new BigInteger(a);
11 BigInteger gBigInteger= bg.multiply(new BigInteger(b));
12 System.out.println(gBigInteger);
13 }
14 }
15 大数除法：
16 package com.my.lucene;
17 
18 
19 import java.math.BigInteger;
20 
21 
22 public class test {
23 public static void main(String[] args) {
24 String a = "15432321321223123231321"; String  b = "2121212121214354343544354354";
25 BigInteger bg = new BigInteger(a);
26 BigInteger gBigInteger= bg.divide(new BigInteger(b));
27 System.out.println(gBigInteger);
28 }
29 }

View Code

大数相减：

 1 package com.my.lucene;
 2 
 3 
 4 import java.math.BigInteger;
 5 
 6 
 7 public class test {
 8 public static void main(String[] args) {
 9 String a = "15432321321223123231321"; String  b = "2121212121214354343544354354";
10 BigInteger bg = new BigInteger(a);
11 BigInteger gBigInteger= bg.subtract(new BigInteger(b));
12 System.out.println(gBigInteger);
13 }
14 }

View Code