Question

Does anyone have experience with java? If yes, please quickly take a look at my code. I am writing code for modular exponentiation, and I am getting the wrong output :(

Answer 1

String binaryexponent = Long.toBinaryString(exponent);
String reverse = new StringBuilder(binaryexponent).reverse().toString();

for (int i = 0; i < reverse.length(); i++)
{
if (reverse.substring(i, i + 1).equals("1"))
{
answer *= ((long) Math.pow(base, Math.pow(2, i))) % modulus;
System.out.println(Math.pow(2, i));
}
}
answer %= modulus;

Answer 2

And suppose that all my variables have been declared.
When I take out the casting for long on the 8th line, I get a different output. Why does it do that?

Answer 3

I don't understand what you're trying to do really, but here's a method I made not too long back that calculates exponents in modular arithmetic. You can try it out there, I have an example commented ready to run.


https://repl.it/EtlR/3

Answer 4

YES AND YES AND YAAAAAAS

Answer 5

Ooh 0_0, thank you so much @kainui
lol @Miracrown