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

Strange that nobody has mentioned it earlier but in java 9 you have sqrt in BigInteger, so you can just use it like that:

BigInteger nine = BigInteger.valueOf(9);
BigInteger three = nine.sqrt();

https://docs.oracle.com/javase/9/docs/api/java/math/BigInteger.html#sqrt--

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EDIT-1

Adding that there is another flavour of this function that, in addition to the floored square root, also returns the remainder.

sqrtAndRemainder() BigInteger[]

Returns an array of two BigIntegers containing the integer square root s
of this and its remainder this - s*s, respectively.