Splitting a 200 bit hexadecimal bitmask

Question

I have a bitmask of 200 bit stored as a hexadecimal value. In order to apply the & bit operator, I have to first convert the hex to an integer but 200 bit is too big for a uint64 so my question is : how do I split my bitmask in 4 different hexadecimal value without loosing data?

So that I can also split my 200 bit data and then compare every chunk of data with the corresponding chunk of bitmask without altering the result.

I do not mean the format, I mean the C# data type (C# does not have a "hexadecimal" data type). — Sergey Kalinichenko, Mar 04 '15 at 14:06
Oops sorry I am reading the data and bitmask from files so it's in a string — ESD, Mar 04 '15 at 14:07
Then the first step will be to convert the input string to an array of integers (byte/short/int/long), then you will need to perform an bitwise AND operation for all entries in the array. — Binkan Salaryman, Mar 04 '15 at 14:10

xanatos · Answer 1 · 2015-03-04T14:16:00.480

You can use the BigInteger from System.Numerics (it's a separate assembly):

BigInteger bi = BigInteger.Parse("01ABC000000000000000000000000000000000", System.Globalization.NumberStyles.HexNumber);

VERY IMPORTANT: prepend a "0" before the hex number! (because BigInteger.Parse("F", NumberStyles.HexNumber) == -1, while BigInteger.Parse("0F", NumberStyles.HexNumber) == 15

BigInteger implement the "classical" logical operators (&, |, ^)

Requires .NET 4.0

score 0 · Answer 2 · answered Mar 04 '15 at 14:10

0

The most efficient way of achieving this is writing a class that can store and do binary operations on 200bits of data, have strings as input, etc.

answered Mar 04 '15 at 14:10

sithereal

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Splitting a 200 bit hexadecimal bitmask

2 Answers2