Guava – LongMath.mod方法与实例

Guava的LongMath类的mod(long x, long m)方法接受两个参数x和m，并用于计算x在m下的模数值。

语法:

public static long mod(long x, long m)

参数： 该方法接受两个参数x和m，它们都是长类型的，用来计算x对m的模数。

返回值： 该方法返回x对m的模数，它将是一个小于m的非负值。

异常: 如果m<=0，该方法mod(long x, long m)会抛出ArithmeticException。

以下例子说明了mod(long x, long m)方法。

例1 :

// Java code to show implementation of
// mod(long x, long m) 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 x1 = -77;
        long m1 = 4;
  
        long ans1 = LongMath.mod(x1, m1);
  
        // Using mod(long x, long m)
        // method of Guava's LongMath class
        System.out.println(x1 + " mod "
                           + m1 + " is : " + ans1);
  
        long x2 = 22;
        long m2 = 6;
  
        long ans2 = LongMath.mod(x2, m2);
  
        // Using mod(long x, long m)
        // method of Guava's LongMath class
        System.out.println(x2 + " mod "
                           + m2 + " is : " + ans2);
    }
}

输出:

-77 mod 4 is : 3
22 mod 6 is : 4

例2:

// Java code to show implementation of
// mod(long x, long m) method of Guava's
// LongMath class
import java.math.RoundingMode;
import com.google.common.math.LongMath;
  
class GFG {
  
    static long findMod(long x, long m)
    {
        try {
            // Using mod(long x, long m)
            // method of Guava's LongMath class
            // This should throw "ArithmeticException"
            // as m <= 0
            long ans = LongMath.mod(x, m);
  
            // Return the answer
            return ans;
        }
        catch (Exception e) {
            System.out.println(e);
            return -1;
        }
    }
  
    // Driver code
    public static void main(String args[])
    {
        long x = 11;
        long m = -5;
  
        try {
            // Function calling
            findMod(x, m);
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

输出:

java.lang.ArithmeticException: Modulus must be positive

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