HDU1063 大数 java

Posted 2020-08-15 LuZhiyuan

Exponentiation

Time Limit: 2000/500 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 9107    Accepted Submission(s): 2654

Problem Description

Problems involving the computation of exact values of very large magnitude and precision are common. For example, the computation of the national debt is a taxing experience for many computer systems.

This problem requires that you write a program to compute the exact value of Rⁿ where R is a real number ( 0.0 < R < 99.999 ) and n is an integer such that 0 < n <= 25.

 

 

Input

The input will consist of a set of pairs of values for R and n. The R value will occupy columns 1 through 6, and the n value will be in columns 8 and 9.

 

 

Output

The output will consist of one line for each line of input giving the exact value of R^n. Leading zeros should be suppressed in the output. Insignificant trailing zeros must not be printed. Don‘t print the decimal point if the result is an integer.

 

 

Sample Input

95.123 12

0.4321 20

5.1234 15

6.7592 9

98.999 10

1.0100 12

 

 

Sample Output

548815620517731830194541.899025343415715973535967221869852721 .00000005148554641076956121994511276767154838481760200726351203835429763013462401 43992025569.928573701266488041146654993318703707511666295476720493953024 29448126.764121021618164430206909037173276672 90429072743629540498.107596019456651774561044010001 1.126825030131969720661201

 

 

Source

East Central North America 1988

题意计算一个浮点数的多少次幂。

代码：

第一次用java写题.

java中高精度实数类 BigDecimal。

BigDecimal add(BigDecimal augend) ：加法 

BigDecimal subtract(BigDecimal subtrahend) ：减法 

BigDecimal divide(BigDecimal divisor) :除法  　 

BigDecimal pow(int n) ：乘幂

BigDecimal multiply(BigDecimal multiplicand) ：乘法

BigDecimal stripTrailingZeros() 返回数值上等于此小数，但从该表示形式移除所有尾部零的 BigDecimal。

BigDecimal toPlainString() 返回不带指数字段的此 BigDecimal 的字符串表示形式。就是直接显示，不用科学计数法表示。

 2 import java.util.Scanner;
 3 import java.math.BigDecimal;
 4 public class Main {              //用Main起名才能在oj上编译通过
 5     public static void main(String[] args){
 6         Scanner cin=new Scanner(System.in);
 7         while(cin.hasNext()){
 8             BigDecimal a=cin.nextBigDecimal();
 9             int b=cin.nextInt();
10             String s=a.pow(b).stripTrailingZeros().toPlainString();
11             if(s.charAt(0)==‘0‘)
12                 s=s.substring(1);
13             System.out.println(s);
14         }
15     }
16 }