Java LongMath.checkedPow(long b, int k)用法及代碼示例

CheckedPow(long b，long k)是Guava LongMath類的一種方法，該方法接受兩個參數b和k，並用於查找b的k-th冪。

用法:

public static long checkedPow(long b, long k)

參數：該方法接受兩個參數b和k。參數b稱為基數，它升為k-th的冪。

返回值：此方法返回b的k-th冪。

異常：如果b的k-th的冪在有符號長算法中溢出，則checkedPow(long b，long k)方法將引發ArithmeticException。

以下示例說明了上述方法的實現：

範例1：

// Java code to show implementation of 
// checkedPow(long b, long k) method of 
// Guava's LongMath class 
  
import java.math.RoundingMode; 
import com.google.common.math.LongMath; 
  
class GFG { 
  
    // Driver code 
    public static void main(String args[]) 
    { 
        long b1 = 5; 
        int k1 = 7; 
  
        // Using checkedPow(long b, long k) method 
        // of Guava's LongMath class 
        long ans1 = LongMath.checkedPow(b1, k1); 
  
        System.out.println(b1 + " to the "
                           + k1 + "th power is:"
                           + ans1); 
  
        long b2 = 19; 
        int k2 = 4; 
  
        // Using checkedPow(long b, long k) method 
        // of Guava's LongMath class 
        long ans2 = LongMath.checkedPow(b2, k2); 
  
        System.out.println(b2 + " to the " + k2 
                           + "th power is:"
                           + ans2); 
    } 
}

輸出：

5 to the 7th power is:78125
19 to the 4th power is:130321

範例2：

// Java code to show implementation of 
// checkedPow(long b, long k) method of 
// Guava's LongMath class 
  
import java.math.RoundingMode; 
import com.google.common.math.LongMath; 
  
class GFG { 
  
    static long findPow(long b, int k) 
    { 
        try { 
  
            // Using checkedPow(long b, long k) method of 
            // Guava's LongMath class 
            // This should raise "ArithmeticException" as 
            // b to the kth power overflows in 
            // signed long arithmetic 
            long ans = LongMath.checkedPow(b, k); 
  
            // Return the answer 
            return ans; 
        } 
        catch (Exception e) { 
            System.out.println(e); 
            return -1; 
        } 
    } 
  
    // Driver code 
    public static void main(String args[]) 
    { 
        long b = 20; 
        int k = 25; 
  
        try { 
  
            // Function calling 
            findPow(b, k); 
        } 
        catch (Exception e) { 
            System.out.println(e); 
        } 
    } 
}

輸出：

java.lang.ArithmeticException:overflow

參考： https://google.github.io/guava/releases/20.0/api/docs/com/google/common/math/LongMath.html#checkedPow-long-int-

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注：本文由純淨天空篩選整理自Sahil_Bansall大神的英文原創作品 Java Guava | LongMath.checkedPow(long b, int k) method with Examples。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。