avt.DynamicFlashRotator.Net.RegCore.Cryptography.BigInteger.sqrt C# (CSharp) Метод

        public BigInteger sqrt()
        {
            uint numBits = (uint)this.bitCount();

            if ((numBits & 0x1) != 0)        // odd number of bits
                numBits = (numBits >> 1) + 1;
            else
                numBits = (numBits >> 1);

            uint bytePos = numBits >> 5;
            byte bitPos = (byte)(numBits & 0x1F);

            uint mask;

            BigInteger result = new BigInteger();
            if (bitPos == 0)
                mask = 0x80000000;
            else {
                mask = (uint)1 << bitPos;
                bytePos++;
            }
            result.dataLength = (int)bytePos;

            for (int i = (int)bytePos - 1; i >= 0; i--) {
                while (mask != 0) {
                    // guess
                    result.data[i] ^= mask;

                    // undo the guess if its square is larger than this
                    if ((result * result) > this)
                        result.data[i] ^= mask;

                    mask >>= 1;
                }
                mask = 0x80000000;
            }
            return result;
        }

        //***********************************************************************
        // Tests the correct implementation of sqrt() method.
        //***********************************************************************

        public static void SqrtTest(int rounds)
        {
            Random rand = new Random();
            for (int count = 0; count < rounds; count++) {
                // generate data of random length
                int t1 = 0;
                while (t1 == 0)
                    t1 = (int)(rand.NextDouble() * 1024);

                Console.Write("Round = " + count);

                BigInteger a = new BigInteger();
                a.genRandomBits(t1, rand);

                BigInteger b = a.sqrt();
                BigInteger c = (b + 1) * (b + 1);

                // check that b is the largest integer such that b*b <= a
                if (c <= a) {
                    Console.WriteLine("\nError at round " + count);
                    Console.WriteLine(a + "\n");
                    return;
                }
                Console.WriteLine(" <PASSED>.");
            }
        }