How can I find the Square Root of a Java BigInteger?

Question

Is there a library that will find the square root of a BigInteger? I want it computed offline - only once, and not inside any loop. So even computationally expensive solutio

Answer 1

I needed to have the square root for BigIntegers for implementing the quadratic sieve. I used some of the solutions here but the absolutely fastest and best solution so far is from Google Guava's BigInteger library.

Documentation can be found here.