Java Guava | LongMath.checkedPow(long b, int k) method with Examples

checkedPow(long b, long k) is a method of Guava’s LongMath Class which accepts two parameters b and k and is used to find the k-th power of b.

Syntax:

public static long checkedPow(long b, long k)

Parameters: The method accepts two parameters, b and k. The parameter b is called base which is raised to the k-th power.

Return Value: This method returns the k-th power of b.

Exceptions: The method checkedPow(long b, long k) throws ArithmeticException if the k-th power of b overflows in signed long arithmetic.

Below examples illustrate the implementation of the above method:

Example 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);
    }
}

Output:

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

Example 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);
        }
    }
}

Output:

java.lang.ArithmeticException: overflow

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