Prerequisite: BigInteger Basics
The Java.math.BigInteger.modPow() method returns a BigInteger whose value is (thisexponent mod m ).
If exponent == 1, the returned value is (this mod m) and if exponent < 0, the returned value is the modular multiplicative inverse of (this-exponent). The method throws an ArithmeticException if m <= 0.
Syntax:
public BigInteger modPow(BigInteger exponent, BigInteger m)
Parameters: The method accepts two parameters.
- exponent: This parameter refers to the exponent.
- m: This parameter refers to the modulus.
Return Value: The method returns a BigInteger object whose value is ( thisexponent mod m ).
Exceptions:
- ArithmeticException: If (m <= 0) or the exponent is negative and this BigInteger is not relatively prime to m.
Examples:
Input: biginteger1 = 23895
exponent = 15
biginteger2 = 14189
Output: 344
Explanation:
result = biginteger1.modPow(exponent, biginteger2)
23895^15 % 14189 = 344
Input: biginteger1 = 6547890621
exponent = 4532415
biginteger2 = 76543278906
Output: 1039609179
Explanation:
6547890621^4532415 % 76543278906 = 1039609179
Below program illustrates the Java.math.BigInteger.modPow() method:
Java
// Code to illustrate modpow() method of BigIntegerimport java.math.*;import java.util.Scanner;public class GFG { public static void main(String[] args) { // Create 3 BigInteger objects BigInteger biginteger1, biginteger2, result; // Initializing all BigInteger Objects biginteger1 = new BigInteger("23895"); biginteger2 = new BigInteger("14189"); BigInteger exponent = new BigInteger("15"); // Perform modPow operation on the objects and exponent result = biginteger1.modPow(exponent, biginteger2); String expression = biginteger1 + "^" + exponent + " % " + biginteger2 + " = " + result; // Displaying the result System.out.println(expression); }} |
Output:
23895^15 % 14189 = 344
Reference: https://docs.oracle.com/javase/7/docs/api/java/math/BigInteger.html#abs()
