Generating very large random numbers java

java random biginteger largenumber
Jeel Shah picture Jeel Shah · Nov 23, 2011 · Viewed 12.6k times · Source

How can we generate very large random number in java? I am talking something like 10000 digits? I know we have to use BigInteger but how can we do this? What is the most efficent way of doing something like this? Please provide a small example. Thank you.

Answer

Jaco Van Niekerk picture Jaco Van Niekerk · Nov 23, 2011

Well, one way is to go to Random.org and download a one of the binary random files. The files are generated from atmospheric noise, so it's very random. I used it for Zobrist keys in my chess engine.

Alternatively you could go

BigInteger b = new BigInteger(256, new Random());

which will give you what you want. In this example, a BigInteger consisting of 256 bits.

Related questions

How to generate a random BigInteger value in Java?

I need to generate arbitrarily large random integers in the range 0 (inclusive) to n (exclusive). My initial thought was to call nextDouble and multiply by n, but once n gets to be larger than 253, the results would no longer be …

Read More
How do I generate random integers within a specific range in Java?

How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum); // Bug: `randomNum` can be bigger than `maximum`. Attempt 2: Random rn = new …

Read More
Getting random numbers in Java

I would like to get a random value between 1 to 50 in Java. How may I do that with the help of Math.random();? How do I bound the values that Math.random() returns?

Read More