Java中的 BigInteger pow() 方法

Java.math.BigInteger .pow(int exponent)方法用于计算 BigInteger 的乘方，作为指数传递的某个其他数字的幂，其值等于 (this) ^exponent 。此方法对调用此方法的当前 BigInteger 执行操作，并将指数作为参数传递。
句法：

public BigInteger pow(int exponent)

参数：此方法接受一个参数指数，它是这个 BigInteger 应该被提升到的指数。
回报：
此方法返回一个 BigInteger，它等于 (this) ^exponent 。
例外：
参数指数必须为正数（指数 >= 0），否则将引发ArithmeticException 。
例子：

Input: BigInteger1=321456, exponent=5
Output: 3432477361331488865859403776
Explanation: BigInteger1.pow(exponent)=3432477361331488865859403776. 
321456^5=3432477361331488865859403776

Input: BigInteger1=45321, exponent=3
Output: 93089018611161
Explanation: BigInteger1.pow(exponent)=93089018611161. 
321456^5=93089018611161

下面的程序说明了 BigInteger 类的 pow() 方法
示例 1：

Java

// Java program to demonstrate
// pow() method of BigInteger
 
import java.math.BigInteger;
 
public class GFG {
 
    public static void main(String[] args)
    {
 
        // Creating BigInteger object
        BigInteger b1;
 
        b1 = new BigInteger("321456");
        int exponent = 5;
 
        // apply pow() method
        BigInteger result = b1.pow(exponent);
 
        // print result
        System.out.println("Result of pow operation between BigInteger "
             + b1 + " and exponent " + exponent + " equal to " + result);
    }
}

输出：

Result of pow operation between BigInteger 321456 and exponent 5 equal 
to 3432477361331488865859403776 
 

示例 2：

Java

// Java program to demonstrate
// pow() method of BigInteger
 
import java.math.BigInteger;
 
public class GFG {
 
    public static void main(String[] args)
    {
 
        // Creating BigInteger object
        BigInteger b1;
 
        b1 = new BigInteger("12346");
        int exponent = 6;
 
        // apply pow() method
        BigInteger result = b1.pow(exponent);
 
        // print result
        System.out.println("Result of pow operation between BigInteger "
             + b1 + " and exponent " + exponent + " equal to " + result);
    }
}

输出：

Result of pow operation between BigInteger 41432345678 and exponent 6 equal to 5058679076487529899393537031261743031889730764186441745527485504 
 

示例 3：
当作为参数传递的指数小于零时，程序显示异常。

Java

// Java program to demonstrate
// pow() method of BigInteger
 
import java.math.BigInteger;
 
public class GFG {
 
    public static void main(String[] args)
    {
 
        // Creating BigInteger object
        BigInteger b1;
 
        b1 = new BigInteger("76543");
        int exponent = -17;
         
        try {
   
        // apply pow() method
        BigInteger result = b1.pow(exponent);
 
        // print result
        System.out.println("Result of pow operation between " + b1
                           + " and " + exponent + " equal to " + result);
          }
        catch (Exception e) {
            System.out.println(e);
        }
 
    }
}

输出：

java.lang.ArithmeticException: Negative exponent 
 

参考： Java : Java ( Java)