Java 大整数加减乘除

目录

题目传送门

题目描述

Java 大整数

分析

代码

加

import java.util.Scanner;
import java.math.BigInteger;
public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        BigInteger a,b;
            a=input.nextBigInteger();
            b=input.nextBigInteger();
            System.out.println(a.add(b));
        }
    }

减

import java.util.*;
import java.math.BigInteger;
public class Main {
    public static void main(String args[]) {
        Scanner input = new Scanner(System.in);
        BigInteger num1 = input.nextBigInteger();
        BigInteger num2 = input.nextBigInteger();
        System.out.println(num1.subtract(num2));
    }
}

乘

import java.util.* ;
import java.math.BigInteger ;
public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in) ;
        BigInteger m,n;
        m=input.nextBigInteger();
        n=input.nextBigInteger();
            m = m.multiply(n) ;
        System.out.println(m);
    }
}

除

import java.util.*;
import java.math.BigInteger;
public class Main {
    public static void main(String args[]) {
        Scanner input = new Scanner(System.in);
        BigInteger num1 = input.nextBigInteger();
        BigInteger num2 = input.nextBigInteger();
        System.out.println(num1.divide(num2));//相除
        System.out.println(num1.remainder(num2));//余数
    }
}

时间复杂度

参考文章

java 高精度 四则运算

java的大数处理对于ACM中的大数来说，相当的简单啊；

整数的运算 BigInteger

小数的运算 BigDecimal

导入类：

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

java 大数相除不能整除时会抛出异常，解决办法，设置精度；参见：java之BigDecimal

 num1 = num1.divide(num2,10,BigDecimal.ROUND_HALF_EVEN); 
    System.out.println(num1);

算阶乘时也可用；

需要转化一下

[复制代码](javascript:void(0)😉

1 int n = cin.nextInt() ;
2         BigInteger m = BigInteger.valueOf(1) ;
3         for(int i = 1;i<=n;i++){
4             m = m.multiply(BigInteger.valueOf(i)) ;//int 整形转化为 BigInteger  进行计算
5         }
6         System.out.println(m);

[复制代码](javascript:void(0)😉

//输入两个大数进行加法运算 add() 相加

[复制代码](javascript:void(0)😉

 1 import java.util.Scanner;
 2 import java.math.BigInteger;
 3 public class dashu {
 4     public static void main(String[] args) {
 5         Scanner input = new Scanner(System.in);
 6         BigInteger a,b;
 7             a=input.nextBigInteger();
 8             b=input.nextBigInteger();
 9             System.out.println(a.add(b));
10         }
11     }

[复制代码](javascript:void(0)😉

//输入两个大数相减 subtract () 相减

[复制代码](javascript:void(0)😉

 1 import java.util.*;
 2 import java.math.BigInteger;
 3 public class dashu {
 4     public static void main(String args[]) {
 5         Scanner input = new Scanner(System.in);
 6         BigInteger num1 = input.nextBigInteger();
 7         BigInteger num2 = input.nextBigInteger();
 8         System.out.println(num1.subtract(num2));
 9     }
10 }
11

[复制代码](javascript:void(0)😉

//输入两个大数相乘 mulitiply () 相乘

[复制代码](javascript:void(0)😉

 1 import java.util.* ;
 2 import java.math.BigInteger ;
 3 public class dashu {
 4     public static void main(String[] args) {
 5         Scanner input = new Scanner(System.in) ;
 6         BigInteger m,n;
 7         m=input.nextBigInteger();
 8         n=input.nextBigInteger();
 9             m = m.multiply(n) ;
10         System.out.println(m);
11     }
12 }

[复制代码](javascript:void(0)😉

//两个大数相除 divide() 相除 remainder() 余数

[复制代码](javascript:void(0)😉

 1 import java.util.*;
 2 import java.math.BigInteger;
 3 public class dashu {
 4     public static void main(String args[]) {
 5         Scanner input = new Scanner(System.in);
 6         BigInteger num1 = input.nextBigInteger();
 7         BigInteger num2 = input.nextBigInteger();
 8         System.out.println(num1.divide(num2));//相除
 9         System.out.println(num1.remainder(num2));//余数
10     }
11 }
12

[复制代码](javascript:void(0)😉

posted @ 2022-03-11 21:19  VanHope  阅读(424)  评论(0)  编辑  收藏  举报