Message7661

This appears to be because of java.math.BigInteger().toString(16)

The following code

// -=-=-=-=-=-=-=-=-=-=-=-=-=-

import java.math.BigInteger;
import java.util.Random;

public class BigIntTest {
     
    public static void main (String args[]) {
        String numString = "1";
        for (int power = 1 ; power < 23 ; power++) {
            BigInteger b = new BigInteger(numString);
            long start = System.currentTimeMillis();
            String s = b.toString(16);
            System.out.println(power+"("+numString.length()+" digits): took " + ((System.currentTimeMillis() - start)/1000) + " seconds");
            numString = numString + numString;
        }
    }
}

// -=-=-=-=-=-=-=-=-=-=-=-=-=-

Outputs the following (I didn't let the code finish, it was taking too long)

1(1 digits): took 0 seconds
2(2 digits): took 0 seconds
3(4 digits): took 0 seconds
4(8 digits): took 0 seconds
5(16 digits): took 0 seconds
6(32 digits): took 0 seconds
7(64 digits): took 0 seconds
8(128 digits): took 0 seconds
9(256 digits): took 0 seconds
10(512 digits): took 0 seconds
11(1024 digits): took 0 seconds
12(2048 digits): took 0 seconds
13(4096 digits): took 0 seconds
14(8192 digits): took 0 seconds
15(16384 digits): took 0 seconds
16(32768 digits): took 0 seconds
17(65536 digits): took 2 seconds
18(131072 digits): took 9 seconds
19(262144 digits): took 37 seconds
20(524288 digits): took 150 seconds