the BigInt is basic operands.
the BigInt is power exponent of base.
the BigInt is modules to be modular of base ^ exponent.
The power modulus value of (base ^ exponent) % modulus.
for powmod
BigInt base = BigInt("123456789012345678901234567890"); BigInt exponent = BigInt("1234567890123456789012345678901234567"); BigInt modulus = BigInt("1234567"); BigInt result = powmod(base, exponent, modulus); assert(result == 359079);
Fast power modulus calculation for BigInt operands.